I’d like to add that part of the problem, for me at least, is that in addition to trying to remember which setting affects what and any associated formulas, you have to remember how/where to access the settings—which button to press or wheel to turn, which screen it was on, etc.

I’m still having a hard time with focusing points. I know how to change the setting, but still don’t really get how the ones in the viewfinder work. When I first got the camera I intuitively understood setting the focus point on-screen in live view, but since my T3i doesn’t have a touchscreen, using the cross keys to move it around can be frustratingly slow.