A Thanksgiving Conversation

A:  Do you remember how we met?

B:  We met at the August picnic. In 1969.  I insulted you.

A:  You insulted me?  That's hard to believe. What did you say?

B:  I don't remember.

A:  If you don't remember, how do you know that you insulted me?

B:   You told me so.

A:   I told you? I don't remember that you insulted me, and I don't remember telling you that you did. 

A:   You did tell me. About twenty years ago.

B:   I've forgotten about that. What did I say you said?

A:   I forget.