There are many reasons why kids get bullied. There is no unified theory of bullying that explains it all.
For years I thought I was picked on because I was smarter than my peers. Looking back, it seems more likely that I was really kind of a brat about getting better scores on things. There were plenty of smart kids at my school who didn't get picked on.
I'm pretty sure the people who bullied you were to blame for you being bullied! Continue to be a brat about those better scores, it encourages the rest of us and sometimes it puts a bigger brat in their place.
For years I thought I was picked on because I was smarter than my peers. Looking back, it seems more likely that I was really kind of a brat about getting better scores on things. There were plenty of smart kids at my school who didn't get picked on.