The essence of a conversation in the car this morning with Enfant Terrible No. 1 which started from talking about a young woman (26) who has recently lost her father to whom she was very close.
To come to terms with our mortality - which could be called Wisdom - we need to do two things, from my experience:
(1) live in the present - as opposed to religion which usually tries to convince us that there is a future beyond death (meditation is one way to regularly drag yourself back to the present) - this is the best way to make use of the limited time you do have, appreciating and using every moment (which does not mean you need to be constantly active/productive)
(2) decide what you want to do with your time - will you use it for yourself or others? ultimately it is most satisfying to do the latter.