Train of Thought

Amy was rambling on and on and something or another when she got distracted (not an uncommon thing).

Amy: And then.....uhhh....Then I.....um. I just lost my thought of train. No, wait. That's not right. I...lost my...thought....of train....my train thought...I can't remember the saying. You know, the one Mom always says when she forgets what she was saying. Oh! I lost my thought of train! No, wait...is that what I said before? I think it is...Whatever, I don't even know what I was saying anyways.

Me: It had something to do with trains.

Amy: Yeah! No, I meant before.

Me: I know.