I had the advantage or disadvantage of a programming background, so I knew two things are needed book, a dead tree typne, with a linux coverdisc, by Andersen. It presented linux in an organized manner, so one could understand the stuff that mattered: the heirarchical file system, security and permissions, when, where, why, and so on. With an ever growing collection of printed google hits, it was easy to miss the forest for the trees. Whenever I was challenged, the book was my first resort; the book is dog-eared now, but still intact. The CD is still in that sleeve, in case some alien decides to try an OS and he happened to have an optical drive in his shuttle.
And I tried something that wasn't covered in the book. Not enlightenment; e16 was already close to 'going gold'. The second thing I got was a used monitor. Hooked up to a first-gen nvidia, I made sure it could match everything that Windows could do. With e17, it far exceeded my expectations. I try to connect a second screen whenever possible. This was before *buntu, and thinkpads had 'IBM' not lenovo, and they were thick enough to stop a bullet.
Mr BeGo is right. Think of it this way, you decide that 'good in linux' meant 'able to boot from a USB stick that
you made yourself'. Well you already know that, so you change good in linux to be equivalent to 'no gui desktop'. Then later you realize the goalposts keep moving or shifting.
Sometime later you realize that good in linux really meant 'good enough to get hired to administer a hospital network'. For now, you can join the legions that can say I'm familiar with it. Later on in life, you will take that 'good in linux' out of its protective case and use it. Or use it tonight, against your smart alecky younger sister, to proclaim I'm good in linux and you're not. nya nya nya