Should I learn LWJGL/OpenGL

So I have been learning Java and using it for around 8-9 months now, I have created mostly games but nothing major. All created using LibGDX.

I feel as if I want to learn a bit more low lever stuff, I want to take a bash at making Space Invaders, Snake and what not but using LWJGL or something similar.

Currently as it is, I mainly use LibGDX for it’s nice game loop and spritebatching, such thing as the camera and Box2D are trivial at best for what I want. Don’t need physics and won’t need a very advanced camera.

However I have studied some game loops and created 1-2 and really, it is simple enough and I don’t think I would need a super efficient sprite batching system in order to re-create old arcade games.

That does not mean I would not like to create one though, what you guys think?

Am I in for a shock if I do decide? I have had a look at the Wiki and SHC’s tutorials briefly and it seems “ok”.