This is normal. I could have said the same thing at one point. I still stick to my comfort zone. I switched from C/C++ to java only because of direct PNG support. and I couldn't for the life of me figure out how to load a png with c++.
I never learned 3d and cannot really do the math for it so I am stuck in 2d. OpenGL DX? Pft. Guy I been programming for fun for longer than you've been alive and I still don't know that junk.
I know OpenGL (the Fixed Function Pipeline; i.e. legacy code). I know most things for OpenGL except: lighting, shaders, bump mapping, multi-texturing and perhaps a few more things here and there. Other than that, I'm comfortable with OpenGL, just I think I try to abstract OpenGL too much than what I should... :l