Already in a brief life, the engaging 18-year-old has attained the ambition of playing for the club he has always supported and has, almost incidentally, scored a winner against the greatest team in the world.
A new contract suggests that riches, further success and continued good health lie in the future.
Watt, quietly and unaffectedly, yesterday reflected on a past that has contained its share of illness but has invested him with the determination to look at his life positively and to help those less fortunate than himself.
The conqueror of Barcelona was part of a contingent of Celtic players who visited the Royal Hospital for Sick Children at Yorkhill, Glasgow, this week to distribute gifts.
It was a familiar surrounding for the player Celtic signed from Airdrie United in 2011.
"When I was younger I had to go to Yorkhill to be treated for asthma and my sister Alana had something wrong with her heart, so she had to go there for years,'' he said
"So, going there to visit the children, I knew what to expect but it really brings you back down to earth and shows you how lucky you are. Some of these kids don't get the chance to live, some don't see past their first or second birthday. Luckily enough for me I'm 18, healthy and playing for the best team in the country, so I know I couldn't ask for much more.''
His trials with asthma were testing.
"I was still young when I had to go in so I don't remember too much but I think I had to stay overnight a few times,'' he said. "My sister had to have operations but now she is fine and for that I'll always be thankful to Yorkhill. I'll always try to give something back to the hospital. If I ever see someone in the street collecting for Yorkhill I'll always help and see what I can do for them.''
Watt, of course, is the very acme of the strapping centre forward.
"Fortunately, I just grew out of my asthma. I came to the conclusion that I didn't really need inhalers any more so I stopped using them. But I used to take asthma attacks when I was playing football as a kid. It was scary at the time, I was only a young boy – I was in primary 7 at the time – and it obviously didn't help my football.
"But I never worried that it might stop me from becoming a professional footballer. I was too young to think about that and to me it was just one of those things."
He can now ponder a trip to Arbroath tonight where he will play a part in Celtic's attempt to dislodge a stubborn Gayfield side from their Scottish Cup ambitions.
He dismissed any fears that the foreign players in the side would be a victim of a culture shock on the east coast.
"They are good enough players to deal with that and get by it. They've seen the glamour of the Champions League and now they have to see the not so glamorous Gayfield,'' he said.
"Last year, it was Peterhead away – and that was even worse! Trust me.''
He is confident that the road to further glory this season runs through Arbroath.
"We want to win every competition we are in and while people say we've had a slow start to the season we are in the last 16 of the Champions League, top of the SPL and in the semi-final of the League Cup already.
"So it's not such a bad season after all, is it?'' he said with the satisfaction of a man who knows he is experiencing the best of life.