This book is written by James Bach, a high school drop out turned software tester extraordinaire, about his life long journey of self-education. I've always looked up to people like this. The idea that being really good at what you do without having gone through some kind of university for a degree is a sexy idea, for lack of a better word.
I wiki all the time, and I usually end up chain-reading links on related topics until I can't see what the tab reads on my browser anymore. Then I just create new browser windows and keep going until Firefox inevitably crashes. Ok, I lied about the last part, but I do wiki a lot.
I've always been one those people that had a hard time doing well in school. Sitting in a lecture and taking exams was not my cup of tea. It's still surprising to me that I've made it this far without having to repeat anything. I learn a lot better on my own, without some syllabus or course curriculum telling me what I need to know. In many ways, I don't agree with the shove-down-your-throat method of teaching employed at pretty much every school out there. I'm rebellious in nature, and I hate being forced to do anything.
However, like the author, academia is not what I'm opposed to. Some of the most interesting stuff I learned were through research papers written by PhDs. Still, I believe it's important to maintain the ability to have the curiosity to learn outside of class or work regardless of whether or not a class environment works for you.
The key word here is curiosity. One can attempt to self-educate by reading about something they don't care much for only to fail at the end, but if the person dived into a topic because of a genuine curiosity it becomes very self-fulfilling. The chain of topics you end up visiting becomes incredibly vast.