Oh man. It's not as bad now with shaders, but I remember how horrible learning fixed pipeline OpenGL was. You'd try to write some simple code, the result would

Oh man. It's not as bad now with shaders, but I remember how horrible learning fixed pipeline OpenGL was. You'd try to write some simple code, the result would be a black screen, and you'd just keep adding glEnable/glDisable calls to your code over and over until you figure what invisible piece of global state was ruining your day.