I love the marshmellow test: place one marshmellow in front of a person; tell them they can eat this one now or they’ll got another marshmellow if they wait for the tester to come pack.  Oh the pain of waiting!  This video says it all.  It shows how we struggle with long term vs. short term gains.  It takes discipline to take the long-term approach.

Oh, The Temptation from Steve V on Vimeo.