There are Honors courses for Math 53, 54 and 113 as well as 104 and 185 at Berkeley, if you can get in. These are for the elite math students and go way more in-depth than the regular classes.
Also by and large, many math majors will have already taken Multivariate Calculus (Math 53) and Linear Algebra/Differential Equations (Math 54) while in HS, often as dual credit. These students would start at Math 55 or beyond.