A man orders three drinks at once at a bar and drinks all three then leaves.

He repeats this ritual every Thursday at the same bar. One day the bartender asks why he orders three drinks to himself at one time instead of spacing them out. The man explains its a pact with two other friends that live in other parts of the country. We all go have three drinks on Thursday so we are still drinking together. The bartender laughs and sets down the drinks. Several months pass and suddenly the man is ordering two drinks at a time. After a couple Thursday's of this the bartender asks, not to pry, but did something happen to one of your friends? The man replies as he takes a sip. No. I quit drinking.