Practice tends to make the information gone for me. When i've heard it once I know it PERMENANTLY but when people repeat it, It sounds more complicated each time which makes me doubt what I did before so I have to start again.

It isn't so much that practice makes perfect as much as practicing makes you as perfect as you can get at whatever you are trying to do.

Practicing does help a lot though, I mean I used to never do my homework and now that I do I have realized that it helps me with my tests. Even if you do not know how to do your homework, but you keep doing the same problems, you will eventually figure it out, regardless if you didn't know you were doing it wrong before.