What is the opposite of stoicism?

I’d say hedonism. And it does, yes.

Epicureanism. It has throngs of adherents.

Oh, yes, and epicureanism. Both.

Libertinism is the opposite of stoicism. Libertinism is the embrace of indulgence and a lack of self-restraint and is a form of hedonism.

Jocularity. There are a number of meetings for people like this. They usually show up to the meetings in a Clown Car.

^^ Is it a VW Bug? 8)