Doing significant research is intrinsically hard... We can't be sure whether we're asking the right question... if we don't feel stupid it means we're not really trying. ... Science involves confronting our `absolute stupidity'. That kind of stupidity is an existential fact, inherent in our efforts to push our way into the unknown.At the end, he notes that "reasonable levels of confidence and emotional resilience help" which I think is a vast understatement. What else will keep you eagerly stupid, if not confidence and emotional resilience? -- especially since there is a whole world out there where the ex-graduate student can feel quite intelligent on a daily basis.
Part of what I've puzzled out in my graduate studies so far has been this: how do the professors do it? They seem to know which questions to ask in order to achieve meaningful answers and progress in research. Some of it is the buckshot approach: they have had the time to ask a hundred little questions, and the odds are in their favor: some of them hit a research target and became published papers. But also, they have an ineffable sense of which sorts of problems are good for research: this is summarized in the adjective "interesting," as in "that is an interesting research question" or "that is an interesting approach to this problem." I've learned that "interesting" is a key word, in bright flashing red letters, that indicates I'm doing Something Right with my research and should Keep It Up.
So while I curate my sense of academic stupidity, I'll continue to rely on my advisors' subtle (subconscious?) nudges and explicit advice.
This post's theme word is nescient, "lacking knowledge or awareness." The experts in the field are those most aware of their own nescience.