"I'm trying to remember something I forgot."
Ernie's head is really more football-shaped. No wonder he can't remember the basketball!
(Of course, for those of you to whom "football"="soccer ball", that joke doesn't work. Oops.)
I relate to Ernie's problem here. I have a bad habit of forgetting things that are right in front of me, or even right in my hands (especially if I happen to have a lot of stuff in my hands, I have trouble keeping track of it all.)