Hope you had a GREAT birthday, OM. Welcome to the 5th Decade Club, of which I am a proud and happy member until 7 months from now, at which time I graduate to the next level.
It's true what they say, that age is only a state of mind, and your best years are still ahead of you. Not necessarily the most productive, but the best.
You're probably ahead of the curve, OM, but the forties are where recklessness begins to turn to prudence and caution, and where knowledge and experience turns to wisdom.
Yes, the forties is the decade during which I think we most become acutely aware of own mortality, but with the right mindset that depressing reality can be put in the back of the mind, and the utterly miraculous notion that we should be so lucky even to be alive at all, can be put to the fore so that life can be relished to the fullest each day we have left in this miracle we call life.