Giving someone value more than the value that he or she expect is not something normal and needs some kind of medical treatment because this person could cherish from this to his or her favor what happens in the half of the cases for example.Thinking about your girlfriend all the time means you are obsessed with your girlfriend. Obsession can be clinical, in other words thinking too much about your girlfriend can be a mental health issue. When you are too obsessed, you will also become too possessive., and when you are too possessive, you will start thinking of your girlfriend as a possession. This can lead to a dangerous behavior.