Robin Williams Does Mill Valley. A lot.

One of the great unkept secrets of living in Mill Valley is Tuesday Night Comedy Night—"Mark Pitta and Friends"—at the 142 Throckmorton Theater. Local comedian Mark Pitta, who looks a lot like a young Charlie Rose, and has a Jon Stewart-like delivery, does a great job hosting the event.

But the main reason Comedy Night tends to be standing room only (like, buy tickets at least a day in advance) is that San Francisco resident Robin Williams and Mill Valley resident Dana Carvey tend to show up, unannounced. Our neighbor, who goes pretty often, says Williams has been performing there about once a month, and bet that Williams would be there last night. He was.

Williams is so prolific, it's easy to take his genius for granted and forget how unusually gifted he is. You can tell that performing for a room this small is what (we bet) he loves most. (Does he even get paid for this? Doubtful. We wouldn't be surprised if he paid to do it.) Supposedly, he and Carvey use the Throckmorton to work out new bits.

Williams tends to look as if he's channeling something—something very funny and chaotic. We assume he's basically taking dictation from himself, noting the good bits and saving them for later.

One thing we especially loved last night was his riff on Mill Valley, which he says closes down at 8 p.m. He launched into the character of an old town crier, swinging a bell: "It's 8 o'clock! It's 8 o'clock! Everyone inside!" So funny! But you probably had to be there.