Ooo, I wish I could have just clicked what was written here! That sounded like serious fun. The truth isn't quite so exciting. I'm old (I'm sparing you a picture) and though I tutor Maths at a very, very lowly level, I only got as far as what would be Further Maths A'level now. But that was nearly half a century ago. Hey! This site does say all levels, OK? Why am I here? I was working through Roger Penrose's Road to Reality and got to chapter 10 and realized I needed more maths (much, much more). So now I'm struggling with Tristam Needham's Visual Complex Analysis...