Mass Effect " ... someone else might have gotten it wrong ..."

I don't think the distinction between "stupid / non-stupid" is the important one to make. The important distinction, imo, is between "honest" and "dishonest".

If someone wants to honestly learn the answer to something, how could this be a stupid question? Even if all other people in the world do, in fact, know the answer, it still wouldn't qualify as a stupid question if asked in good faith.

However, there are so many questions asked in bad faith and not coming from a desire to learn something. These are the real stupid questions.

So, to answer your question: if you're feeling stupid for asking something, just think about your intentions: do you ask because you honestly want to know the answer? Go ahead, and know that in this case there are no stupid questions - only stupid answers.