How do you get over gifted kid syndrome in high school/study tips?

Take harder and harder classes so you don’t get bored and just coast on your natural ability. Take more APs/IB classes.

Start self-studying for AP courses that aren’t taught at your high school. You can teach a few of them to yourself.

If those are easy, start taking community college classes after normal school in harder subjects.

At some point, you will need to study.