The other day someone stopped and asked why I wasn't smiling. At that moment, I was sitting by myself, staring off into the distance. Let's think about that for two seconds: why would I be smiling at such a moment? And have you ever seen another human being sitting by themselves smiling for no apparent reason, and not thought, "Here is a person who may well be insane"? Am I wrong because, when I see someone walking down the street, smiling to themselves, I think, "Jeez, what's his problem?"
Anyway, it made me think of a couple of old bits, the first from Dr. Katz (the relevant bit is at 0:28, if it doesn't line up right):
The second is from my exemplar in life: