Still, it seems like a stretch. Not so out of character that I'll quit reading though.
Well, of course Superman is behaving out of character. That's part of the story.
And Lois isn't actually thinking that Superman has done anything. But please remember the red K episode, or that first season episode where Superman was hypnotized. He did strange things then, things you would call "out of character". That's why Lois was investigating in the first place. I don't think that Lois would blindly trust in the innate kindness of even Superman after the Luthor experience. And after all there are more than enough evil criminals at hand to make Superman behave out of character, one way or another.
I don't think Tahu ever complained that any of my characters actually behaved out of character.
The dream is not a memory in the strict sense of it. Clark, as you may remember, was already gone when Lois talked to Superman. Later on I will tell you what Superman actually said to her that night. The dream is more or less a mixture of her worst fears and some memories.
