The comedian Steve Allen said people laugh at 2 things --
First they laugh at things that make them feel superior like someone else falling on their derriere.
Second they laugh at something unexpected, which is really making fun of yourself because you expected something all along and you got tricked.
The bottom line is you laugh because someone made a fool of someone else or made a fool of you
If you want to write something funny write something that makes someone else look stupid and therefore makes others feel superior or write something that is totally unexpected which tricks the reader who feels stupid for making false assumptions.
