The very first whiff of coffee when you just open the can.
A laughing baby everytime
An act of kindness
Nah---I usually teach them everything they need to know.
(I am now ducking and running for my life.)
My first question to potential dates has always been "Let's see a couple of your 5 page or better research papers. And they had better have footnotes in the proper style." I didn't get many dates.