Grandma, sitting in bed, proclaims "Hmmm -- I fancy a bowl of ice cream right now".
Grandpa, who is walking around, quickly suggests "Oh, I'll go get you a bowl, dear."
"You old fool", she replies, "you'll just go to the kitchen and forget why you're there. It'll be faster if I get it".
"No, no, no honey. A bowl of ice cream - simple. I'll be right back" he says as he shuffles off the the kitchen.
However, as he stares into the fridge, he can't quite remember what he's supposed to fetch for his wife. He decides that she wanted some eggs and so he quickly scrambles up a couple for her.
He returns to his wife with the plate of eggs and a fork and immediate hears:
"You old fool! I knew you'd forget!! Where's the bacon(烤肉)?!"