Maybe you leveled the mountain? :-P Being "on" the mountain while not being willing to opine just seems like a strange use of words.
Does Mount Stupid refer to the observation that people tend to talk loudly and confidently about subjects they barely understand (but not about subjects they understand so poorly that they know they must understand it poorly)? In that case, yes, once you stop opining the phenomenon (Mount Stupid) goes away.
Mount Stupid has a very different meaning to me. To me it refers to the idea that "feeling of competence" and "actual competence" are not linearly correlated. You can gain a little in actual competence and gain a LOT in terms of "...
A little knowledge is a dangerous thing, not sure what the official name for this particular cognitive bias is (feel free to enlighten me). Probably most of us can recognize that feeling of enlightenment after learning a bit of something new and exciting, and not realizing yet how far it is from the mastery of the subject. I suspect that learning the LW brand of rationality is one of those. (Incidentally, if the words "LW brand of rationality" irked you, because you think that there is only one true rationality, consider how close you might be to that particular summit of Mt. Stupid.) See also the last bullet point in the linked comic strip.
As an exercise in rationality, I suggest people post personal accounts of successfully traversing Mt.Stupid, or maybe getting stuck there forever, never to be heard from again. Did you find any of the techniques described in the sequences useful to overcome this bias, beyond the obvious of continuing to learn more about the topic in question? Did you manage to avoid turning Mt.Stupid into the Loggerhead range?
My example: I thought I was great at programming fresh out of college, and ready to dispense my newly found wisdom. Boy, oh boy, was I ever wrong. And then it happened again when I learned some more of the subject on the job...