Robin Williams stopped by David Letterman yesterday and told a story about taking an acting class taught by Marlon Brando several years ago, which leads him into doing his Brando, Nicholson, and Walken impressions. Sure, they’re like the three of the most common celebrity impressions ever, but Williams is still good at it. Also, I’ve never seen Robin Williams let a talk show host say so much during an interview. David Letterman gets out a double-digit amount of words, which is a record for anyone interviewing Robin Williams.