What happen to this guy? Did I do something wrong?

It seems to me that perhaps he wasn't entirely sure that you liked him or like him as much as he liked you, and he was hoping that you would start initiating contact but when you didn't (or didn't as much as he would have liked you to) he got discouraged and gave up. If this is the case it would seem like he was looking for something really uncomplicated and didn't want to exhaust alot of energy on it (if he just got out of a relationship that would support this). As far as you doing something wrong, that's pretty much a judgement call, different people have different ideas of who should do what when it comes to this kind of thing.