don't mean to offend or pick on anyone, but you really should make the effort to go to the lectures. I admit that I didn't go to all my lectures, but in hindsight, I think I should have...
Reason? The lecturers I know actually put some effort and thought into what they teach, even if they have done it dozens of times before. You might say, "they get paid to do it". Fair enough, but you should appreciate that it is a difficult thing to stand at the front of the lecture room and teach a bunch of people. They make an effort, so should the students.
"I already know the material, it's all in the lecture notes"? That's not a valid reason to not turn up to lectures. You may already know the stuff, so it's revision to you. Good! There are sometimes little things that are put up, which you don't already know, among the things you do. The lecture notes are usually not complete and things are added to it. They really should only be taken as a guide to the lectures themselves - not replace the lectures.
"Attendance records are not kept in lectuers, No-one knows that I'm not there"? You do.
OK
\end rant.