They do say that you never can tell who, if anyone, will turn out to be a hero - there's no way to know until the crunch comes.
And sure enough it can often be the least likely person who is already on their way across no-man's-land, while the rest of us are still looking around for someone else to come and help.
So often it's the person with the most to lose who is the first to risk it all on behalf of others, those least able to carry the burden who somehow manage to bear it all.
It's also often the circumstances that bring out the hero in people - something shaped by the needs of the moment and the instinct of an individual to get stuck in for the greater good.
All this is true. But all this and more doesn't begin to explain the heroic standing of Captain Sir Tom Moore. For this man was already a hero in ways conventionally understood: he served in the Duke of Wellington's Regiment during the Second World War, fought in the 'forgotten army' in Burma, now Myanmar - also sadly in the news this week - and then lived a long and happy life serving the community to the grand age of 100.
But at 99 - how extraordinary - he set off on his own bat on his rollator to walk around his garden to raise funds for the National Health Service.
In the genius of that selfless act, in the simple humanity of caring for others, Captain Tom galvanised a nation and became a global icon.
What no one could predict was that, sometimes, a hero's steps are taken so painfully and painstakingly that the whole world follows, pace for pace.
And this ancient gent accumulated the incredible total of almost £33m in sponsorship.
Many accolades followed; much fame, also; last July he was knighted by the Queen personally, her first engagement since lockdown.
In what has been described as a war against Covid-19, Captain Moore displayed conspicuous bravery in what we now know was very much indeed "the presence of the enemy".
One look at this Yorkshire man with his dapper silver moustache and you were reminded of our fathers and our grandfathers. A generation we perhaps did not understand fully but one infused with a sense of duty, an understated valour, an unfussy bravery.
Captain Tom wasn't a statesman, scientist, politician or entertainer. He was "just" an old man who wanted to help people. And he did, in so many ways. With his simple motto "Tomorrow will be better" he kept the people in good heart and, like him, looking forward to a world without a pandemic.
What we feared was that the unthinkable would happen, that he would not make it through himself. But amidst the sadness of today there is the hope that he suffered little, the sense too of a life so utterly fulfilled and memorable that it will be remembered for every right reason there is. How fitting it was that his last hours were spent in the care of the institution for which he cared so much and for which he had literally offered his last days.
Odd as it is, his last gift to us is the quiet dignity of his own departure and its unique quality.
Now we have the chance to witness in our time what not many do - that strange process whereby a genuine hero first comes into being and then how that remarkable person is gathered up in the love and respect of millions, as if carried shoulder high.
In other times, it would be the Abbey for Captain Tom. It might still be.
There are none in that august company of the historic dead who wouldn't shuffle over a few feet to make room for the remains of this gallant man.