I used to laugh out loud sometimes when I wrote it... I'd think of some things my characters would say, and even if I couldn't use it, I would write the scene out just to let them loose on something - my private show.
Well, all these things I would just laugh about and think about for so long and put them in. And then I'd think, that's just plain indulgence. Take it out! And I'd take it out.
A couple of learning points from that, fairly familiar ones, but worth reiterating for all that. Firstly, getting into the mind of your character. If you can't hear them and know what they'd say, how they'd react in any given circumstance, they aren't real and you haven't got into it yet.
Secondly, the old adage of 'kill your babies'. Yes, by all means write out that wonderful dialogue that makes you laugh and helps you understand the character. But unless it's actually saying something that progresses the story, it has to go.