I have an M.Sc. in Maths, mostly differential equations, but some
relativity & quantum mechanics. All very rusty, because that was
thrity years ago, and I've worked as a software developer ever since.
I've retained an interested in maths & physics whenever I have some
spare time.

I found RTR in a bookshop a year ago, and I'm enjoying it, but finding
it hard going, especially because I've found it a good exscuse to
digress into other areas such as non-eucldiean geometry.