The 4 Types of Brothers
You're around the same age and it's usually a lot of fun. But watch out, it can lead to getting in all sorts of trouble (see Menendez Brothers).
He'll follow you around and your parents will force you to include him in everything you do, but until they robot butlers like in Rocky or The Jetsons, this is the closest you're getting to a personal servant.
Always there to buy you beers or bail you out of jail. But remember, he's also always going to be there to borrow money when you're older.
You were most likely a mistake or maybe one of your parents got remarried, or both. Now you have a brother who is about 20 years older that you have nothing in common except a loose love for your parents and the local NFL football team.