"I am grown older by a great many years since my first publications, which were in the year 1580: but I very much doubt whether I am grown an inch the wiser. I now, and I anon, are two several persons; but whether better, I cannot determine. It were a fine thing to be old, if we only traveled towards improvement; but ‘tis a drunken, stumbling, reeling, infirm motion: like that of reeds."
Michel de Montaigne, Essays Book III, Chap 9.
The above quote from Montaigne very nicely addresses the fallacy that with age comes wisdom. The 'me' of today is not the 'me' of 1979 or 1994, we are three different people. But the 'me' of today has to live with the consequences of the good and bad decisions made by those people back then. For some things, I'd like to go back and thank them for what they did, and for other things I'd like to go back and shake those idiots for their poor judgement. But, even if we could do that it would not matter, we are here now. We must continue on from where we find ourselves in this constantly changing present, hopefully responding to the new events we encounter that require our judgement and decisions in a manner such that the 'we' of the future will look back upon favorably. Can we learn from our 'mistakes'? I think not, the circumstances will be different, the mistake then may be the proper course now, or vice versa. Do we even know what our 'mistakes' were? What we classify as a 'mistake' may be the singular event that made us what we are. The mistake may be in deeming some past decision to have been a 'mistake'.