Three men were using the urinals in a public restroom in DC.
The first man finished relieving himself, zipped up, strolled to the sinks and proceeded to wash his hands, using plenty of soap and water and doing a splendidly thorough job.
As he was drying his hands (with lots of paper towels), he loftily announced to no one in particular “At Harvard, I learned to be clean and sanitary. “
The second gent zipped up, marched briskly to the sinks, and scrubbed his hands with much less soap and water than the first man, doing a splendidly thorough job nonetheless.
As he was drying his hands (with only one paper towel), he severely announced to no one in particular, “At Yale, I learned to be clean and sanitary, but I ALSO learned to be thrifty and environmentally conscious. “
The third man finished relieving himself, zipped up, and ambled past the sinks to the door, muttering to himself, “In kindergarten, I learned not to piss on my hands. “
This joke is included in the Black Book of Jokes. You can order it from here.