So this may confuse people but when you grow up with someone who is 12 years older than you it's like you're an only child. Yes, you watch them grow up but you don't have to deal with the same issues. They leave for college and you're still very much a baby. You get spoiled like an only child because your parents had time to prepare themselves for another kid. You get your own attention and you're barely compared to your older/younger sibling because they are in a different point in life. More often than not I feel like an only child with a best friend as opposed to a little sister.
Now, in saying that, I love my brother to pieces. He is always there for me even when I don't know it. He is the best thing I can remember about my childhood. Always having the person to look up to and aspire to be like. It's awesome. Even when he gets mad and refuses to accept the fact we are related, he can remember when he was my age and everything gets fixed or goes back to normal. I can never imagine my life without him and sometimes, I even wish he wasn't so much older than me.
Having the ability to basically be raised as an only child was great but often times it caused me to be shy or withdrawn. My brother was always there to pull me out of my shell or encourage me to extend my horizons. Basically what I'm saying is that if you have a sibling be there for them through think and thin. Don't ever write them off for being annoying or mean because one day they might not be by your side 24/7. In fact I advise you to go bear hug that twerp right now... maybe call them an affectionatly nerdy pet name and bake cookies. I won't judge.