You probably shouldn't get into serious relationships!

Because they don't want to go through the fact that if there not perfect then they are nothing, but some just think that their not perfect! Well, hope this helps you in a way!

You can start by saying hi and how are you! Good Luck!

Well it most likely means that he likes you more then a friend! If you like him more then a friend though, try not to flirt back, you will just end up with problems!