I would definately say alot of crashes on the Ring are due to people thinking they know it, but they don't. It's a long track, that to the unfamiliar eye all looks the same. My Dad smashed his Z3 M Coupe due to getting over-confident after 3-4 trips thinking he knew the track, but didn't, came off at Wehrseifen, which after miss-hit-miss it a very slow tight bit which, if you're not expecting it will only end in tears.

As RW said, it's not hard to learn at least where the track goes and the general line from videos, track notes and even GT4! Track knowledge is sooo important there.