Learning stuff that doesn’t help in work(calculus is not helpful for 99% of software engineering) is really hard if you don’t base it in reality I find. Maybe it’s just me but I would never read a text book for fun so suggesting learning by reading a text book seems crazy. Calculus can be fun and interesting but the teacher has to actively try to make it so. The learning will take longer but you’re more likely to see it through and I think it’s more likely to stick long term too.

I learned way more reading crafting interpreters than I did in my compiler class for example.