I definitely don't think porn affects us that way unless we allow it to. I think that most people who watch porn are well aware of the fact that it's not reality (unless they've never actually had sex before).

My boyfriend says that he learnt all his moves from porn and if that's the case, I have a lot of thanking to do to the porn industry. I've never found porn to affect anything other than my self-esteem on the rare occasion (normally when I already feel pretty low), so I don't generally buy into the concept of it deeply changing anything about my sexual self.