I used to take Ritalin regularly after my ADHD diagnosis.

I kept it in my purse.

One day, I thought, “Oh, I must take my Ritalin.”
I opened my purse, forgot what I was doing, took out a $2 coin, put it in my mouth…. Oops. I didn’t mean to do that.

I then took the coin from my mouth, wiped it off, put it back in my bag, and forgot to take my Ritalin.

All a very good example of ADD brain in action, really.