Imagine a situation where Bob asks Dave: Dave? Why didn't you come to my birthday party on Monday? Dave replies: "Monday I was busy torturing kittens."

In most cases, if someone would tell me that they torture kittens in their spare time I first impulse wouldn't be to conclude that they are actually torturing kittens.

The kind of person who can openly joke about torturing kittens in their spare time is likely high confidence. In some social contexts that joke will still get you looked down upon. Knowing what kind of jokes are acceptable and having the ability to push to that limit demonstrates social savviness.