When babbling makes sense

The crazy guy sat alone on the park bench, babbling to himself.

He didn't notice the woman behind him. She watched him deliver an impassioned monologue, comprised of seemingly extraterrestrial utterances, to the evening air.

The woman likely thought he was speaking in tongues, or Klingon. Perhaps she thought he was another severely mentally-ill citizen who had slipped through the holes in the United States' social safety net and landed in the park, where he likely also slept.