While this might sound a little too psycho for your liking, it doesn’t actually mean that they actually have a split personality. When someone likes you, there are times when it seems that they are more open and friendly with others, then suddenly clam up when you’re around. It isn’t that they aren’t the same person, it’s more about them not wanting to screw anything up with you. They just wanted to make sure that they don’t do anything stupid to screw up any chances of you actually liking them back.