Sometimes, if you are lucky, you get to relive a moment from an ill-spent youth.
So, as a paid-up member of the Baby Boom generation that rocked and rolled in the pop heyday of the swinging '60s, I revisited old memories at Slane Castle last Saturday.
Ah! The 1960s, the decade that appears to have been the era when indeed it was bliss to be young and alive. You don't have to take my word for it.
In this newspaper, there is a feature called 'Focus' in which individuals are asked a set number of questions, one of which queries which era they would like to have been brought up in. The Swinging '60s is the choice of a surprisingly large number.
But, perhaps it is not a surprise, for this decade has emerged as the decade that stands out in the 20th century; the Roaring '20s is the only other period that comes near it.
Ten years or so littered with icons and world shattering events: the assassination of Kennedy, first man on the moon, the Vietnam war, the building of the Berlin Wall, 'Lady Chatterley's Lover', Che Guevara, et al.
But, enough of the heavy stuff, of much more interest was the explosion of good old rock and roll.
And, what an explosion! An avalanche of music that has stood the test of time. Is there anyone at all who can't recognise the opening notes of a cascade of '60s hit tunes.
The Beatles were the Golden Boys of pop. But, they had a squeaky clean appearance. The Rolling Stones, on the other hand, had a much raunchier, down at heel, altogether scruffier aura surrounding them.
A particular news feature item in the 'London Evening Standard' posed the question, "Would you let your daughter marry a Rolling Stone?" The answer presumably was a very definite negative.
They were to use an old fashioned term, Beatniks. Much more appealing to a rebellious teenage generation which, of course, knew it all and were desperate to adopt anything that the older generation disapproved of.
The more things change, the more they remain the same. The 'ugliest group in pop' was one of the descriptions of the Stones and the subsequent decades have wreaked extra havoc.
But, popular music, at least in those bygone days, had little to do with appearances. The music is what counted. And what music!
So, off to see the Stones, their first visit here in a quarter of a century.
First task though was to repair to a house where refreshment was provided, to get the batteries charged, so to speak. Amazingly, I seemed to be the oldest person there. An astonishing number of people in their late teens, twenties and early thirties.
It drove home the message that the '60s and the Stones, who were one of the most iconic symbols of that louche decade, still count.
Having got the foundations in, on then to the venue in the company of thousands of suitably clad fellow punters. Everyone knew that this was not going to be a sedate tea party on the lawn, so there was little in the way of sartorial elegance.
And the arena at Slane. A natural amphitheatre, perfect for the task of hosting a pop concert. A field sloping down to a castle with the river streaming past and beyond that, rising woodland and open fields. If it had been a sparkling, sunny, summer evening, it would have been truly spectacular.
Still, early in the evening, so the time was whiled away by listening indifferently to the various support groups and watching a constant stream of helicopters swooping in to discharge the crème de la crème.
The rural, rustic Ireland of De Valera's whimsy of dancing at the crossroads was another world completely.
What the founding father of the State back in the 1920s would have made of it all, God only knows. Was it for this that they fought and died? Presumably not, but this is what we've got.
And so, an hour late, the main attraction appeared with a blaze of lightning that lit up the darkening sky.
I would have to say that, for this punter, it was a bit of an anti climax and really I should have known that this was inevitably going to be the case. You see, I was a Stones fan in the '60s and early '70s but, for some 30 years their career simply passed me by. The only Stones songs I know come from that halcyon era.
Ridiculous to expect that their set would be confined to the hits of those long past years.
So, it became in one sense an endurance test but, of course, Jagger and co. would inevitably throw in a selection of the songs that are the foundations of their appeal.
And, so, in the end, I did get to provide raucous backing vocals for some of the timeless anthems of a misspent youth. The long departed guitarist Brian Jones, he of the flowing blond hair, once explained what the Stones were all about: "What we want to do is bring a lot of satisfaction to people, thereby earning a bomb."
The Stones have delivered on both fronts.
N.B. I may have been the oldest man in the pub, but I wasn't the oldest at Slane Castle. Jagger, Richards, Woods and Watts were.
