What a game-changer the Olympics have been. When I was born, London was the largest city in the world. Now there are 30 larger – though it is still the largest in Europe and North America.

We agonised as to whether we had made the right decision to host the games in the first place, though we felt a frisson of excitement at the challenge and dared to hope that we could pull it off. We knew we were a prime and juicy target for a terrorist attack and felt it next to impossible to guarantee that there would be no chinks in our armour.

We fretted over a gridlocked city, militant train drivers going on strike, and whether we could hold our nerve at stage managing such a colossally intricate extravaganza before the focused gaze of the whole world. Most of all – amidst the gloom and despondency of the longest recession in living memory – we worried about the sheer cost of it all. Yet every anxiety has been laid to rest in magnificent style.

The world will long remember these 2012 games and Britain has been showcased as it has never been in its long, long history. It was a project of immense and overarching complexity and we could have been forgiven for our worries as to whether we were any longer up to such a challenge. But that too has been laid to rest. We may not be the titan that bestrode the world when I was born – the only one to look Hitler straight in the eye and not blink – but we remain the repository of immense skills, artistry and organisational powers. The challenges that lie before us are daunting, to say the least, but we have proved to ourselves that however big and complicated they may be, we can cope.

In the past we have acquired something of a reputation for being always able to muddle through, but that can hardly be said of the way we have handled these games. It augers well for great projects like the Thames Estuary Airport; the Bristol Channel tidal energy scheme; the high speed rail link and perhaps anything else we might wish to put our mind to like the extraction of our massive reserves of shale gas.

We have been enthused with a renewed spirit of “can do”. Far from being a nation in decline, we can start to believe that we may be a nation on the cusp of great things again. With our massive reserves of oil around the Falklands, we can become energy-independent again and make ourselves indispensable to our European partners by supplying their needs too – no bad thing in the tough negotiations which lie ahead to repatriate many of the powers we have lost.

As we are all well aware, finance rules the world and the City of London rules finance. Of all metropolises, London seems to be the one that the “movers and shakers” most rave about, buying up real estate wholesale. It is cosmopolitan; tolerant; open; a good place to do business; is perfectly placed – time wise – to transact on the same day with both east and west; boasts an unrivalled theatre-land, along with – at last – good restaurants; and as if all this were not enough, it speaks the world’s lingua franca.

Empire gave us links and goodwill that no other country can match. We have our cosy little Commonwealth Club, spread all over the planet, and we play against each other in our cosy little world of cricket. What fools we have been not to maintain the great trading links we developed over centuries with those who were always best disposed towards us. Had we done so we would not now be so exposed to events on the continent as we are today. Even now it is not too late to reverse this shortsightedness. We should be putting together trade missions with the same zeal and fervour as the missionaries of old who carried the Gospel and opened the way for trade.

Having landed ourselves with the Olympics, we knew that we would be watched as never before for our competence and flair (if there was any) and we surprised the world, not least ourselves.

As for the Paralympics, we even set a new benchmark, having pioneered it – like so much else – in the first place. Disabled people have never in all history felt better about themselves and that is wonderful. In so many respects they took our breath away. Their feats would have outperformed most able-bodied people and they showed guts beyond belief.

In my own humble way I too am bionic – like so many of them – with two knee replacements. I’d be happy – even proud – to stand alongside them, if they would have me. Maybe future organisers should think about a 100m sprint for the over 70s with knee replacements. I’d be up for it in an instant, shouting, “Rio here I come!” The training, I promise, would start at once.

Like many of you (I suspect) I am sad that I could not see all of this wonderful jamboree. But I intend to buy a DVD of the highlights. And there you go! There are some of my Christmas presents taken care of already. For once I wont have to rack my brains for something that will not disappoint.