What if my classmates laugh at me for being stupid?

When she/they laugh at you, they are laughing at her/himself, dear. Don't pay attention to what she/they say. Sometimes the more embarrassed you are, the more she/they push their luck and laugh as a joke. Don't study hard to get rid of her/them just because she/they have influenced you. If you stick to life for so long, you will always meet great people. Open your heart and don't let her/them influence you.