First, learn assembly. Pick a machine architecture — it's not that important. For extra credit, pick multiple machine architectures and do something in each.
Then learn Lisp.
And Morse code.
You'll need Haskell for dat Damas-Milner sexiness.
Wait wait, we need to pile on some Ruby and JavaScript, you don't want to be some sort of weirdo that can't make a web app do you?
Hrrrrm. Yep, need some APL. With Unicode.
That'll really hammer in the concatenative into your brain.
First, learn assembly. Pick a machine architecture — it's not that important. For extra credit, pick multiple machine architectures and do something in each.
Then learn Lisp.