Dude... The cat was inside. I turned around for a second, then turned back and it was outside, in a place it could not get to, unless I put it there. I was shocked to see it outside, so I went outside, picked it up, and brought it inside.

What I remember is the shock that something in the world was not in the same place that I left it. This has never happened to me before or since. This is not rocket science. The people in this thread are over thinking it.