Do you wash your hands after using the rest room?  Of course, you do........but that reminds me of a military joke I heard;

A young army sergeant was urinating in a urinal when a young lieutenant came in to use the urinal next to him.

When the army sergeant finished, he zipped up and proceeded to head towards the door, WITHOUT washing his hands.

The lieutenant abruptly interrupted him, saying; "they taught us at officers training school to always wash our hands after using the rest room."

The army sergeant politely replied; "in basic training, they taught us not to piss all over our hands.