You know more than fresh graduates, but fresh graduates don’t absorb 100% of the material being taught — more like 50% at best, and many promptly forget that knowledge after taking the final. As someone who went back to school after about five years in SWE industry, I did (and still am) learning things in CS classes.

Granted I did know a lot of the material already, and I do go to Berkeley which has a comprehensive CS program, so YMMV. My main point is to not compare your knowledge to fresh grads knowledge to determine what they are taught.