If you haven't gotten stuck in some rocks in a Bethesda game, you haven't played them enough yet to even be considered a novice
Nah, just kidding. It happens a lot if you do a lot of exploring of tight corners of caves, mountainsides, rivers, etc.
Yes. It happens. It can happen with your opponents also. I hit a skeever through a wall. You could hear it trying to attack but when you try to hit it with your sword your sword just hits the wall. It's caused by gaps in the meshes between sections. If you are playing on a computer you can type ~tcl to toggle off collision long enough to get unstuck.
Or between textures and walls.