A member of Kenya's proud Masai tribe he was tending his father's herd of cattle the day the big cat pounced. The terrible injuries the lion inflicted cut out the wonderful light for which the African continent is renowned, rendering Gilbert's world forever dark.
Today, Gilbert is 19, and a student at the Thika School for the Blind that sits in a tranquil backwater of Kiambu County, 25 miles northeast of the Kenyan capital, Nairobi. He is also a footballer, a good one, as are his teammates at Thika who make up Kenya's first-ever blind football team.
Last week was a big week at Thika. Both senior and junior teams were training hard in preparation for the big day in Nairobi's Karura Forest Park when the Queen's Baton relay for this year's Commonwealth Games hosted by Glasgow would arrive in this sports-mad country.
As part of the event, Thika School was to field a number of players in an exhibition match on Monday that would be the first of its kind in Kenya. The match, organised by Thika School in conjunction with social enterprise group, Alive & Kicking and United Nation Children's Fund (Unicef) was to become the centrepiece event.
Also at Karura last Monday along with Gilbert was another much young junior player, 11-year-old Eric Munyao. Like many of the visually impaired children at Thika and across Kenya, Eric is albino.
A hereditary condition, albinism occurs only when both parents have albinism genes resulting in the lack of pigmentation that gives colour to the skin, eyes and hair.
Across Africa albinism can be, quite literally, a death sentence. Not only do many African albinos endure insults, discrimination and segregation, but they have a high risk of contracting skin cancer in a region where many jobs are in the open air under the searing sun.
Albinos' lives too are endangered through mistaken traditional beliefs that their body parts have magical powers. Some albinos have been slain for just that reason, their dismembered limbs sold on by unscrupulous dealers to traditional healers or 'witch doctors' as ingredients in rituals.
But Eric seems oblivious to such things. Other than his albinism he is in every other way just another 11-year-old with boundless energy and a mischievous grin.
"I'm a defender," he tells me proudly, when I ask what position he plays in the Thika team. Eric's look suggests that having watched him play, his role in the team should be obvious to anyone who knows about football, and that I, evidently, am not one of those people.
As we talk I notice he is wearing a blue bush hat emblazoned with the 2006 Melbourne Commonwealth Games logo that shields his very vulnerable skin from the fierce African sun.
"I like being a defender, it keeps me busy, and I like football because I get to make friends," Eric continues unprompted, as if knowing instinctively that this football philistine standing before him needs as much explanation as he can provide.
I find it easy to warm to his directness, his clear determination not to let anyone get the better of him and make the most of the hand life has dealt him.
I felt the same too about Mandela, another footballing defender for whom life has always been difficult but who through the power of sport finds himself a professional player with Nairobi club FC Talanta.
Shela Mandela Sande, to give him his full name, is sitting alongside his Talanta FC teammate, Peter Kamau, as we talk waiting for the arrival of the Queen's Baton relay at Karura Forest Park.
Both grew up as street kids, slum boys for whom football was the only way out of an existence that leaves so many young men like them dead in Kenya.
"I think I started playing football in the womb," says Mandela who was one of seven children when his mother and father separated but not before they had called their son after his great South African namesake, Nelson Mandela.
Very quickly, however, given the instability, poverty and violent climate of the slums, the young Kenyan found himself stealing from "careless" people and running with a "bad crew".
All this time though Mandela was still playing football and came to the notice of talent scouts on the lookout at local matches in his home town of Eldoret. National trials followed and Mandela, along with friend and subsequent teammate, Peter Kamau, found themselves on Kenya's talent development programme that nurtures exceptional young players with the aim of placing them within the FC Talanta team.
For years before his own sporting breakthrough Kamau lived in Nairobi's notorious Dandora district where a giant mountain of the city's waste provides a meagre living and source of food for some families.
In the neighbouring Korogocho slum district there are few schools and the need to find food takes priority over education for most children.
I remember once during a previous visit to the slum coming across a boy no more than 10 years old carrying a string of filthy chicken heads and offal he had retrieved from the dump for his family to eat.
Likewise, Peter Kamau would spend days on the Dandora dump site, scavenging for plastic waste for recycling by unscrupulous companies who would pay him a pittance - 20 Kenyan shillings per kilo.
Such an existence comes with considerable risks. In one test carried out on Korogocho children, more than half had blood abnormalities that signalled heavy-metal poisoning which exceeded accepted international levels. This is said to have resulted from toxic fumes released from the garbage burned there and other chemicals leeching into the soil, water and food chain.
Like Mandela, however, football provided Peter Kamau with his way out of life on the dump. Both young players were given boarding at the talent academy where coaching, nutrition, gym work and tuition in footballing tactics became part of their curriculum. Today, they now play professionally for a salary of 16,000 Kenyan shilling, hardly a fortune by European footballing standards, but a sum beyond the imagining of most Nairobi slum dwellers.
"It lets me look after my family and live with some dignity," says Peter, a small, wiry 19-year-old who is known for his pace.
Both young men are lucky. Just a few days before we met I talked with another young man who was a product of slum life.
For Fredrick Onyango, football too has been pivotal in his life, but not always in a positive sense. As a young gangster in Kibera - Nairobi's biggest slum and the second largest in Africa after South Africa's Soweto - his teammates were also fellow criminals.
"After every football practice we would plan our robberies and targets," he told me as we sat crammed into the claustrophobic shack that was his home in the slum. Death through violence has never been far from Fredrick's life.
Of his 19 footballing friends, seven managed to escape gang life, one is serving a life sentence for robbery with violence, and 10 are dead as a result of shootings or stabbings.
That leaves Fredrick, who one day realised he too would end up dead if he continued with the armed holdups.
Wearing a Glasgow Celtic shirt totally coincidental with my visit, Fredrick explained that where once football was a means of bringing his gang together for mugging, "snatching" and armed robbery today he uses it for constructive ends.
It was Fredrick who initiated an organisation and runs the project known as Greencard Mtaani. Taking its name from the card system used in football refereeing his group aims to mobilise youth through sports and in particular football.
"In football the yellow card is a warning and the red card means the end, we use the symbolism of the green card as a way of suggesting that a person from the slums can go forward to better things," he tells me.
In his role as chairperson of Greencard Mtaani he has been widely accepted by slum youths in the Kibera community and become something of a role model in much the same way as the FC Talanta players.
As we finish our conversation, I ask if he was fan of Glasgow Celtic given that he was wearing the club's colours? "Here in the slum we have a local side called Kibera Celtic, who have been helped in the past by the professional side from your city," he said with a smile.
Like the Commonwealth Games baton relay it was a tangible link with Scotland that last Monday was endorsed at the Karura Forest Park when the baton arrived to the cheers of Kenyan school children and sports enthusiasts many of them waving saltire and lion rampant flags.
Following speeches from British High Commissioner Christian Turner, Kenyan track and field running legend Kip Keino and others, the hundreds of children present were treated to the exhibition match by players from the Thika School for the Blind and FC Talanta.
The event was the result of hard work by Alive & Kicking, an African social enterprise that manufactures and provides sports balls for children, creates jobs for adults and promotes health education through sport.
Working with Unicef and six players from FC Talanta, Alive & Kicking has embarked on a programme to visit six special schools, providing some 400 children and their teachers with specialised coaching sessions and an introduction to blind football.
Alive & Kicking's motto, Made in Africa, by Africa, for Africa rings true with its specially designed hand-stitched "sound balls" that it has been making since 2010.
Each of the balls contain ball-bearing "ringers" which enables visually-impaired players to participate using their sense of hearing rather than sight.
Out on the pitch last Monday at the Karura Forest Park, the hundreds of guests at the baton relay event were shown what can be done with these "balls that make a difference".
Everyone was reminded of how true Nelson Mandela's words were on sport's capacity to create positive things.
"Sport has the power to change the world … it has the power to inspire. It has the power to unite people in a way that little else does. It speaks to youth in a language they understand. Sport can create hope where once there was only despair. It is more powerful than government in breaking down racial barriers."
Out on the turf, another African - Shela Mandela Sande - a Kenyan slum boy now professional footballer named after his parents' South African hero, was putting fellow defender little Eric Munyao through his paces.
Both are children of the Commonwealth of Nations and through sport have found a sense of belief in themselves.
The Herald and Sunday Herald Children of the Commonwealth series will run over the coming months as the Queen's Baton travels the world on its way to Scotland. As well as bringing our readers inspiring stories from key locations on the baton route, we're also raising money for UNICEF, an official charity partner of the 2014 Commonwealth Games in Glasgow. There are a number of different ways to donate: you can call 0800 044 5777; or you can click on unicef.org.uk/herald; or you can text 'CHILD' to 70111 to donate £3. If you prefer, there is a coupon in the Saturday Herald magazine and in the Sunday Herald. UNICEF is the world's leading children's organisation, working to save and change children's lives.