I've got the answer to that question.
God knows, I asked it myself 30-odd years ago. And I asked it in all earnestness. Seriously, I could never imagine a scenario when I would need to know algebra.
But I know the answer now. And when my kids moan and groan and ask that question -- which Daughter is sooooooooo close to asking -- I'll be able to answer honestly and swiftly.
When you have your own children. That's when you'll need to know how to do that shit.