1. Did you like it / were you good at it during elementary / secondary / high school / college years?
Not particularly good at it. Had a horrible teacher in third grade who made it all the worse. I'm pretty sure I had/have dyscalculia--not to the point where I couldn't grasp concepts but to the degree that I was slower in processing numbers, felt left behind, and got no joy.
2. Are you a graduate of a college where mathematics was among the core courses?
Undergrad was music composition. People who like math love to talk about how mathematical music is. People who don't are like, 'Whatever, dude.' (Yes, I see the maths there, but I don't get any jollies from it.)
MA and PhD were in applied linguistics and so statistics is usually around.
3. If yes, do you use it in your current / former job?
Despite my previous answers, I actually teach a course or two in statistics. I've come to appreciate mathematics for its own sake in my middle-aged years and go through spurts where I read books about it.
4. If no, do you think, in retrospective, that learning it during elementary / secondary / high school was of any use?
I fully believe maths should be taught (and not because of the usual balance-your-chequebook BS), though I don't agree with the way it's usually taught where there's no sense of discovery or figuring things out. And where it's all for the test.