How does GL remember how to microwave popcorn, but forget to eat it?

GL loves popcorn. When anyone else makes it, he's sure to come along and sample theirs. He was asking for it so often, it was a great day when he learned how to microwave it himself. But lately, he puts it in the microwave, starts it, leaves the room, and forgets to come back. Once it's cold, he no longer wants it.

So when the microwave beeps,  I have a choice of finding and reminding him now, or throwing his popcorn away later.