Phya, out of all the pro-Mentalist posts, I thinks yours was the most positive one. Positive thinking can do wonders; however, I view it as more of a willingness to try something, as opposed to just believing. It might take a lot of self-motivation or even forcing yourself as you learn a new skill, but it will be worth it in the end, because it’ll bring the good experiences that’ll lead to greater confidence. With most new things, you don’t know if you can do it until you actually try, although if there are things you simply won’t do, that’s perfectly OK. But those things should be kept to a minimum.
Case in point. If someone offered me to participate of a roller derby, I’d say “no thanks”; it’s completely outside my skill set, and I don’t see the benefit in trying it. However, if someone offered me to play a basketball game (I’m bad at it), I’d still say OK, because I might actually have a fun time playing and learn something new, or at the minimum, get some exercise out of it. Next time, the motivation to play might be different, or it might not. The key is finding something to motivate yourself, even if it’s just a nicer alternative to sitting at home. Then the good experiences will come.
It’s interesting that you mentioned the Mentalists “jumping ahead”. Those who say “just be confident” are probably sharing whatever they know best. To explain the concept, let’s use an analogy. Consider an issue all immigrants face (except those who come as little kids): their accent. When asked how to correct it, many native-born Americans will say “just practice speaking English”, because practicing the pronunciation was something they “just did” as kids; that’s what they’ve known their whole lives. (Exceptions to this would be speech therapy providers.) Immigrants, on the other hand, have to learn intellectually how to sound out each English letter: namely, how to use the lips, teeth, tongue, and voicebox to make certain sounds. Without some specific instructions to point all that out, correcting their accent will be a daunting task at best, and might take a lot longer to achieve.
Similarly, for people who were lucky enough to become confident during their formative years, “just being confident” feels as natural as eating when they’re hungry. But for the rest of us, learning to be confident is an intellectual process. So the advice in the thread title really might feel as confusing as “just practice speaking” to a recent immigrant. Now, if this starts an immigration debate on top of the drama that already took place, don’t make me responsible 
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