Don't let age worry you: it's gonna kill you in the end, so why waste time with the worry?
The real problem with age is that you realise that everything is contained within a circle, vicious or otherwise is just fortune. If you knew that - to the extent that you believed it - when young, you'd have a far happier life removed from the horrors of trying to be best at everything when, in truth, you can only be what you already are...
That realisation is one of the rewards of hanging around a long time.
;-)