It started with one cup when you were 17 years old. You probably didn't like the bitter taste, but you just needed a boost to finish that sociology paper before your 8 a.m. class.
Nowadays, you finish your second cup of coffee before even stepping foot into the office. (Or maybe you're on a whole new level, like this this guy who ordered a $50 Starbucks drink.)
courtesy of: http://mashable.com/2013/02/28/evolution-coffee-addict/#D_KcV22suuks