Honestly, it doesn't really matter. I had a friend like this a while ago. This guy was a momma's boy and a loser. I tried everything to get him to attend school, get a decent job and gain some respect...none of which he ever did. He even used to want to borrow things and also smashed my window while drunk one night arguing with his g/f- turns out he felt he shouldn't have to pay in any sort of way since I had sold the car later on afterward. Later on I found out his girl was trying to get back at him by cheating on me. I even told him what's up and invited her over after he said in a number of words he didn't care. The day after he changed his mind...but I already did the damn thing. He finds out, and asks how I can do this to him, blah blah blah...then stops talking to me for a while. Now every now and again he'll try to contact me but I have no respect for him since he got back with that girl- it demonstrated exactly what I needed to prove to myself he would never be a true friend. On top of all this he lies to people, including me- his so-called "best friend".
All I'm saying is you'll have to find your own reasons. Good luck bro.