What is rehab like after ACL surgery?

Necessary. After a severe injury to the knee like an ACL injury & subsequent surgery, the knee is weakened, swollen, painful, and in need of major healing. Without thearpy, one may not gain all of the potential that is left in that injured knee. It may be painful to go through the rehab, but it is necessary. With the right therapy, supervision & medications, you should do well. Work hard. It's worth it!
Difficult! Rehab is not easy, but it is absolutely necessary. The most important thing to focus on initially is regaining full rom, especially extension, and minimizing swelling and pain. Your pt should have a protocol for you to follow as you recover.