"It's called alchemy." Ed's response is just as flat, looking up at Keith slowly as the transmutation fades away like nothing had changed in the first place. "It usually doesn't work here. Something's off." It's not that he doesn't remember the weird weekends, he's just not entirely sure what rules apply the way they did originally. He also doesn't know what Keith is or isn't aware of, which makes that the simplest most straightforward explanation he can think of.