Why do/did you?
Because I have an enormous head and, even if people will continue to think me less competent than a peer with equal performance, at least they won't assume that I'm stupid. Until the last year or so, I've been the most aggressive person I've ever met.
Also because it's easier for other people if someone breaks the ice.
Why would you let it stop you, especially in a center of education [where if you are able to ask questions knowing the answer you really don't need to be there]?
Because you're (in the math department, anyway) just going to be considered more lazy, more stupid, and less worthy of help and attention for every wrong answer you give and every obvious question you ask. Why lower yourself from the default?
That's your own insecurities to deal with. Anyone who believes an entire gender is incompetent isn't going to [even need to] look for proof, it's an assumption based off assumptions.
Why would you think women could possibly be competent at math if all the statistical data you personally gather, from the women in your math classes to your math teachers to who you are told is great, leans hard in a particular direction? It's a leap of faith away from your own experience of averages and availability heuristics, and mathematical people usually don't like those much.
Or perhaps all the women were that much smarter than the men and didn't need guidance. It's pretty easy to jump to conclusions.
No, I'm talking about answering questions in lecture, mostly. There were bonus points given for participation.
You know, being a subject of pity and ridicule does have an effect on many people! We may be hardened veterans in that regard, but many aren't.
Yeah, no intention to sound harsh but there's no other way to say it without sugarcoating it to opaqueness.
I assume that you had a safe haven. Like, say, the math or physics classroom, full of nerds just like you?