My brother is three years younger, and we are not at all close (we live on different coasts, and he lives near my parents). I'm not really surprised, since we have really different personalities and weren't especially close growing up.
Honestly, I don't really like him. He's needy, oversensitive, rude, always plays the victim, and treats my parents like crap despite all they do to support him (seriously, he'd be homeless without them). He keeps cutting them off whenever they do anything that upsets him, which usually consists of refusing to give him money. When we see him (we visit my parents once or twice a year), he complains, pitches fits, pouts about stuff, and otherwise sits around like a bump on a log.
For a while, I felt bad, but it is what it is--we are very different people, I don't enjoy his company at all, and I fully expect that once my parents are gone I will have almost nothing to do with him. I can feel sorry for him, but I can't really like him.
I've tried many times over the years to talk to him, to try to help him, but the only thing he wants is to be told what he wants to hear or to have you give him stuff. And he isn't even minimally polite (like, last time he opened his gifts and did not once say that he liked something, let alone thank anyone). Maybe he'll have an epiphany and decide to get his life together, but it's up to him--there's clearly nothing that anyone else can do.