Going off at a bit of a tangent to the main point, although I haven't used very advanced maths for years, I did LIKE things like calculus in my distant youth. I remember doing Stage 1 Mathematics at University and the last class of the year was a summary of all the Stage 2 classes available. I remember sitting there with a big grin on my face the whole class, wanting to do all of them. Maybe that makes me a little strange.
The next time I had that feeling was in an Intro to Reactive Muscle Kinesiology. I had the same big grin from end to end. I didn't have the anatomy knowledge to do the course, but managed to persuade the tutor to let me do it if I learned a bunch of bones and muscles. Ok, so that even more of a tangent...
Following you now - @sift666 recommended you and I see you checked out my recent post. Look forward to reading more of your posts.
Ya I know exactly what you mean, it can be a pleasure discovering something so elegant and complex as a mathematical theory