There are two possibilities… The most likely is that your friends studied the subject and did their homework while it was being taught rather than waiting until the night or day before and thinking they could learn it all then. It doesn’t work to cram for a test instead of learning as you go through the material… OP, the other possibility is your friends are just smarter than you… Frankly I believe the answer is the first one - They learned as they went through the course.

Isn't AS good? But still good? Still passing? Quit comparing yourself to others. It is hard enough without that stress. You already are competitive with yourself, it appears. That should be the only person you focus on.

There is such a thing as studying wrong. Talk to your teacher and if you can, schedule a time to study with them or attend their office hours.