I always reality check when I'm in reality. Like at least 15 times a day. But when I'm in a dream everything is just, I don't know, believable! The strangest things have happened in dreams and the only times when I become lucid is when I actually start to fly and say "wait, flying is only possible in dreams, so I'm dreaming!".
I've always wondered how I don't become lucid in my dreams, since they're all so strange.