Low level graphics and you

After a long time of meditating on OpenGL I've come down with a bad case of "I don't know how to do anything and only use tools made by someone better than me". Since the only cure for this common programmer illness is more meditating I've decided I want to learn graphics on an even lower level than OpenGL, though finding a guide for this route has proven to be nigh impossible.

I'd appreciate it if a guru could give me a friendly pointer in the right direction or an insight on the things that take place between an OpenGL call and a pixel being displayed onscreen.

At the end of my journey I desire the ability of displaying but a single pixel without the aid of instruments given to me by the masters.

>>10
I was merely pointing out that my goals are humble and I wish to learn for the sake of knowledge and not create something grandiose to avoid off topic replies that don't answer the question but rather criticize my wish of gaining a deeper understanding of the machine.
Example: >>5

After using ZBrush (3D Modeling being a passion of mine aside from programming) I noted it's superb performance and attempted to recreate it using OpenGL with help from OpenCL (the information is scarce but I believe ZBrush isn't even hardware accelerated). I failed to reach speeds comparable to ZBrush and realized there is much much more to know about this field.