I remember in 9th grade there was one kid who complained the entire year about how he would never use algebra. He asked his dad and his dad said he had never used algebra. He must have brought this up 30 times and each time the teacher tried to give practical answers like calculating how much fertilizer or deer feed (we lived in a farming community). He was unswayed. Comically, he gave answers where algebra would be helpful if he knew, but because his dad didn’t know it was difficult (simultaneous solution for cow auction of different types of cows).

Just because you think you haven’t used or didn’t use, doesn’t mean it’s not useful. First, maybe I didn’t use because I didn’t know how to use. Second, maybe there is more to the world than me and the probability of folks needing info is 95% and I’m in the 5% of the lucky/unlucky.

I try to learn things based on curiosity and intrinsic value that I try to estimate. The act of learning is valuable as a system and I’m frequently surprised by putting unlikely topics together.