I have lots of difficulties seeing some stuff while doing technical drawings. Specially when changing from one perspective to another.
This weekend I had four drawings to do. I couldn't "see" any of them. And I tried hard.
I hate that, 'cause this "blindness" doesn't interfere with any technical stuff (all our needs are in 2D and the 3D is pretty obvious). Any more advanced drawing that I need can be done in some CAD program --- or I can draw it.
It is hard to convince my teacher of that... And it's even harder to convince her that I AM trying to draw and to see things.