What seemed unthinkable at breakfast yesterday sounded like old news by lunch time.

Our rapid absorption of the Pope's resignation is a telling example of the demands that proved too great for the pontiff.

In abandoning his post before death claimed him he was breaking with a 600-year convention, yet by noon commentators had moved on to speculate about who would succeed him. Nothing stops the onward march and no-one is indispensable – not even the spiritual leader of one billion souls.

In his resignation bombshell Pope Benedict said: "In today's world, subject to so many rapid changes and shaken by questions of deep relevance for the life of faith ... both strength of mind and body are necessary."

I might not agree with him on everything but in this I do. For centuries the Vatican was a hub of information. Bishops charted political and social developments across the globe. The papacy had time to absorb changes, ruminate on them and in good time proclaim its responses through the pulpits it commanded across the Christian world.

Today the Vatican receives its information at the same time as every man, woman and child with access to a laptop, smart phone, radio or television. In place of measured contemplation, instant soundbites are required. And no sooner have the issues and concerns of Europe been answered than those of Africa or South America will be pressing for a response.

The Pope is at the apex of an empire. He is its monarch, chairman and chief executive. Further, his proclamations on faith and morals are deemed infallible. His thoughts and then his words are what the world awaits. This is no job for an old man. Whomever inherits the triple crown will need the constitution of an ox and a tireless intellect as major challenges continue to buffet this ancient fortress – and vested interests jockey for influence.

We are told there will be a new pontiff by Easter. If there is a motto that should be hung at the entrance of the Sistine Chapel as the cardinals enter the conclave to elect him, it is this: "If we want things to stay as they are, things will have to change."

The last thing the Roman Catholic Church needs is another dyed-in-the-wool conservative. Pope Benedict's seven-year reign has seen numbers shrink in western Europe.

People of faith have found themselves at odds with a church mired in a child abuse cover-up (in which the Pope was implicated in a previous role). They question the stance against homosexuality that is so out of step with equality legislation. They welcome the Pope's hint at tolerance towards condom use when the intention is to save a life but crave an outright lifting of the ban. Many in the West want an end to priestly celibacy and an open door for women clergy.

In this democratic age an authoritarian church needs to re-engage with its people. Clearly this will require a man who is young enough and sufficiently in touch to understand today's world and keep pace with it. Pope Benedict's most intelligent act has been to recognise his own limitations. After all, we allow US presidents to step down after two terms. We watch how British prime ministers age in office. Yet the UK and US combined are but a fraction of the Pope's empire – and he was 78 years old at his election in 2005.

This elderly academic's conservative attitudes might have won him support within the Holy See but they unleashed a hurricane of protest when voiced to the wider world. His early pronouncements included a restriction on homosexual men becoming priests followed less than a year later by a quotation from a 14th-century Byzantine emperor that said Islam brought only evil to the world and was spread by the sword. Within weeks he was joining in prayers at the Blue Mosque in Istanbul – following a public apology.

In 2010 on a visit to Spain he attacked abortion, gay marriage and aggressive secularism. A year later he recalled the papal ambassador to Ireland following an unprecedented rebuke in the Dail when the Irish Taoiseach accused the church of covering up child abuse.

Just four months ago the Pope's butler Paolo Gabriele was convicted of stealing papers from his desk. He said he was trying to protect the Pope who was "a pure man in the midst of wolves". It painted an image of an old man being bamboozled by ambitious underlings. Maybe there was some truth in it. Maybe it tipped the scales.

Now that the Pope has taken this almost unprecedented step, it's obvious the decision is the right one. The practical Dutch monarchy has practised timely abdication since the mid-20th century. The last three queens stepped down, the most recent 75-year-old Queen Beatrix who will hand over to her eldest son, Crown Prince Willem-Alexander at the end of April. "I am abdicating," she said, "because I am convinced the responsibility for our country should now move to the next generation."

With all of us living so much longer, more of us will need to learn to recognise the moment to step back in whatever walk of life. The Pope is clearly compos mentis and may have years of quiet contemplation ahead. But along with intellectual and spiritual stamina, a great office requires a savvy response to political machinations from within as well as without.

For those like Queen Beatrix and our own Queen, there is an argument that the heir should be given the opportunity to step up before they are too old. It is for the good of the heir. It is also for the good of the country. If the heir isn't fit for purpose he (or she) should be disinherited. If they are able, is it fair to block them until their age becomes a disadvantage? Will the country benefit from an untried monarch who is perhaps also out of step with the modern world?

That seems to be what happened in the Vatican. Benedict XVI was the oldest Pope elected for 275 years. The church should be grateful that at the age of 85 he has retained the wit and the wisdom to resign.

Depending on who the next Pope is (maybe South American, maybe African) historians may say this was the moment the Roman Catholic Church entered the modern world.