its probably that he wasnt to fire OP so hes looking for reasons and sowing discontent. Sorry OP, its a common management trick. Even if its not, you might want to look into a new job, cause who wants to work in a place like that.

Well in all honesty, if someone was completely lacklustered and dull one week and suddenly started excessively laughing the following week, I would think that person is just being a smartass. Maybe that's what OP's boss felt.

that is not necessary true... some people are just annoying. But if you don't like your work place, maybe it's a good idea to seek for something else.

This sort of happened to me. I suffer from resting bitchy face so my manager told me I should try to smile more to make customers feel welcomed. Then she told me to stop because my forced smile "makes me look like a serial killer"

They can't exactly move on, not when it's their job ://

I was going to say that maaaannn!