It builds substance - citation neded. It seems like it could just as easily build insecurity, resentment, etc.
Speaking from experience, I can tell you that I know a lot more than any of my peers (I'm 16), and practically all of that is due to the reading I did and am still doing. That reading was a direct result of my isolation and would likely not have occurred had I been more socially accepted. I should add that I have never once felt resentment or insecurity due to this, though I have developed a slight sense of superiority. (That last part is something I am working to fix.)
Reading a ton as a teen was very helpful to me also, but I think I would have still done it if I had a rich social life of people who were also smart and enjoyed reading. Ultimately being around peers who challenge me is more motivating than being isolated; I don't want to be the one dragging behind.
I do feel that I had to learn a fair amount of basic social skills through deliberately watching and taking apart, rather than just learning through doing--making me somewhat the social equivalent of someone who has learned a foreign language through study rather than by growing up a native speaker; I have the pattern of strengths and weaknesses associated with the different approach.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.
To any future monthly posters of SQ threads, please remember to add the "stupid_questions" tag.