I definitely have to agree on using Arch to learn the terminal, and Gentoo is even better for it, but much more time consuming. For that matter, you can learn a lot in any distro by just switching to tty1-tty6. Very useful, especially for trouble shooting. If you stop xorg from loading on boot, it'll really force you to learn a lot, and shave a few seconds off boot time
(though I'd recommend installing w3m or links or something first so you can use Google from the command line lol).