How do you forget?

Well, R awakened this morning and one of my usual questions to her is... "How'd you sleep last night?" She usually tells me of the fantastic dreams she has which are a combination of her imagination and the stories read to her before falling asleep the previous night.

So this morning when I asked her, "How'd you sleep last night?" she responded, "I didn't have any dreams. Least not that I can recall. Maybe I forgot them. How do you forget?"

That tickled my fancy this morning as I tried to determine if she was asking a philosophical question or just wanted a brief response.

How would you respond to that for a 7-year old?