You're probably doing it to yourself regularly.

Ex: Thinking of yourself as stupid or lazy.

It's anti-agentic. Even if it is self deprecating, all good jokes contain truth. A small fraction of you believes your self talk.

Then, after all, if you're stupid or lazy, why bother trying? You won't succeed anyway.

You're unconsciously sabotaging your own motivation.

This ends up feeding your narrative further in a self destructive spiral all the way down.