Actually I wrote it. I wrote “my bad” in an email to Catherine yesterday and she replied “Where does ‘My bad’ come from?”
So I looked it up to answer her and wrote back:
Its a silly saying for ‘I made a mistake’ or ‘I’m sorry’. I usually don’t say it. And I just looked it up and found these:
Is “My Bad” Bad? by Chad Lundgren
and
Substance Musings by Alyssa Wodtke
Oy. I have been properly chastised and won’t say that again!