Onions

My hands smell like onions from a recipe I made last night.  I've caught myself subconsciously smelling my hands several times last night and this morning.  "Why do I keep doing that?" I've asked myself, and the answer came to me just a little while ago.  It certainly isn't the scent, itself!  It's because of the memories it evokes.  Of working at Time Out when I was younger.  It made me wonder what other scents would do this to me... Would the smell of chlorinated pools remind me of Othello?  Orange blossoms of Arizona? And, more importantly, what smells will evoke memories in my children?  Will they subconsciously sniff the air when they get a whiff of pine?  And will they catch themselves doing it again and again because the memories are happy ones?