Manual of Life - Alternate Definitions

Adulthood
n., That moment when you find yourself staring at a parent/elderly relative and realise you haven't really been seeing them as they are, but as they were a decade ago.  

And that you have been doing so for a long time now.  

And, in doing so, have failed to notice that a wholly different person, with wholly different needs, has supplanted the person of your memories - despite your being convinced that you had been carefully monitoring their growing frailties.

And which ends up with you in front of the mirror, trying to recognise yourself as you are today.