Midday today I was reading on a couch in the corner coffee shop, having had a bagel and a small coffee. A guy came in and sat on the couch across from me, talking fast and seemingly to himself, though a companion (who had a dog with her) then sat down with him. The guy seemed nervous, and seemingly on the verge of either laughing or crying. He talked with the woman who was sitting with him; I won't share that part of this, as that would be rude of me, but then the guy needed to get up, and instead of walking past his companion and her dog or around the table and squeezing past me, both of which were perfectly doable (he'd done so earlier), the guy stood up and walked on top of the table. Then came back and walked on top of it again.
He did this quickly enough that one of the people working there didn't have a chance to say "Don't walk on the table" until the guy had done it twice.
WHO WALKS ON TOP OF A TABLE.
The guy, his companion and her dog then left. A man who'd watched from nearby said, "I do not know what just happened."
I hate that a) I had the sinking suspicion that the guy would get more disruptive the longer he was there and b) I was right.