Quit making yourself the punchline before anyone else gets the chance.

Getting there first feels like armor. If you say it about yourself, nobody can hurt you with it, and at least the laugh is on your terms. The cost is that you are teaching the room how to see you, and people tend to believe the advertising. Given enough repetitions, you start believing it too.

Count how many times you do it in a single day. The number is usually surprising. When the opening comes up again, try letting the moment pass in silence and see whether anything bad actually happens.