Robin Williams has always been a bit of a clown. If you remember (how could you not?), one of his most iconic movie roles was the lead in 'Patch Adams,' plus he also played a mime class instructor in the movie 'Shakes the Clown.' Though he may have had an advantage in portraying these characters.

He had some useful experience under his belt that he picked up from working the streets. While trying to find acting gigs for himself in the '70s, Williams greased himself up in white paint and performed as a street mime in front of New York's Museum of Modern Art.