Here are some thoughts I have.

There's no one good definition of funny. I remember wathcing Bob & Ray on the Johnny Carson Show once. My family thought they were hilarious. The studio audience was completely silent - evidently didn't get it at all.

Another time, my husband and I watched a mime on educational TV. Again, the DH and I laughed our heads off. The studio audience was completely silent, probably couldn't understand his act at all.

There are times when I'm the one not laughing. I think much of the humor on TV consists of setting up a victim to look stupid. Then the stupid person is ridiculed. I quit watching shows like that a long time ago. 'I Love Lucy' is an example. I quit watching that show at the age of 10, and I don't understand why people still go on about it.

I agree that incongruity plays a part in humor, at least most of the time. Everything funny is somehow inappropriate. (This doesn't mean that everything inappropriate is therefore funny.)