I remember Jim Woodcock as really inspirational - he was working with my PhD supervisor in 1987. We were working on a variant of Z for specifying what, today, we would call CRDTs. I was also lucky enough to meet Tony Hoare the same year and discuss those concepts.
Jim is an amazing guy. One of the rare people who are absolutely brilliant in their respective field, and are equally good at teaching the subject. He's also just a really kind, nice person who is delightful to chat with, though that's true of pretty much anyone in York [1].
I also think his book "Software Engineering Mathematics" [2] is an extremely approachable book for any engineer who wants to learn a bit more theory.
As I said, my dropped PhD is not a failure in any capacity from my advisors or the school, mostly just life juggling stuff.
[1] I don't know why exactly, but of all the places I've been, York has the highest percentage of "genuinely nice" people. It's one of my favorite spots in the UK as a result.
[2] https://a.co/d/02M25LcY, not a referral link.