This may sound like an odd question but…does your own comedy writing make you laugh? Should it? I’m talking strictly in the rewriting phase, say, five months into a script, should you still laugh consistently as you read through your own work?
No, usually my writing doesn’t make me laugh, at least after the initial how-clever-am-I chuckle. Any joke becomes unfunny after you stare at it for too long. The trick is to remember why it was once funny, and protect those aspects.
While rewriting generally sharpens comedy, it’s all too easy to lose subtle jokes in the process.