A sign of intelligence and insight -- to see the absurdity in things is a sign of an ability to consider things from a different perspective and to think creatively. And to understand you don't need to take everything so seriously.

It is definitely a sign of intelligence....stupid people just get mad.

something else? a by product of a banana split?

It appears to be an aspect of our awareness. The ability to contrast light irony with perpetual drudgery ..and you can’t force or make it up … but you can point it out, or not ~