Answer: This is because you have an imagination of your future girlfriend in advance and the general appearance of your girlfriend has been carved into your brain. It means you are single now, and you dreamed of a girl, but you remember her appearance too clearly when you woke up! This is a normal phenomenon. It is very likely that you will meet this person at some point in the future and feel familiar to you, but she may not really be your girlfriend. You still have to work hard to get a girlfriend.