I am currently trying to learn formal logic and proof systems.<p>I’ve always been interested in learning higher level math, but was consistently mystified by the proofs. I could always come around to understand them, but I never understood how the authors knew that proof method was “allowed”.<p>Learning about the formal proof systems has been a very interesting diversion for me. It has helped me begin to understand the foundations of the math subjects I am interested in and definitely has upped my confidence reading intricate proofs.<p>But perhaps the best outcome of this learning has been that I now have a much stronger framework for sound reasoning. It is easier for me to express and argument clearly or pin down a shortcomings in other arguments.<p>It is unclear to me how applicable these learnings will be for my primary interest in software development, but it has been a very enlightening process nevertheless.
I'm always working on AI stuff, just because that's been one of my "hot button" interest items dating back to the early 1990's. Sadly I didn't make it my career focus for a long time and now I'm kindof playing "catch up" but that's OK.<p>On related note, studying a lot of maths, mainly in service of my interest in AI. I only took up through Calc I "back in the day" and that was like 30 years ago anyway. So trying to bone up on a lot of Calculus, Linear Algebra, Probability, etc.<p>And finally... I've signed up for a class that is one of the "earned entry" classes for an online Master's Degree program (@treprinum here on HN clued me in to that[1], so thanks for that!) and some of the programming assignments require Kotlin, so I'm literally sitting in the cafe at Barnes & Noble right now with my Kotlin book, working on getting up to speed on that.<p>[1]: <a href="https://news.ycombinator.com/item?id=37595773">https://news.ycombinator.com/item?id=37595773</a>
I've been walking every day between 6-10 miles depending on weather for the last 3 months and I have gotten very good at walking, running, and sprinting. I am starting to do some basic agility training like parkour as well. I'll probably stop doing this every day in a month or so but it has helped me develop a good sense about the biomechanics of walking and greatly improved my cardiovascular health.<p>For anyone else that tries this I recommend starting small and then gradually working your way up. I got a bad injury early on from doing too many miles too early. If you don't consistently do cardiovascular exercise then walking a mile or two every few days is a good way to develop the habit.
Maths / stats / data science / ML stuff, alongside my PhD (building science / energy efficency) research. I haven't yet even found out when the in-person lectures are for the current thing I'm signed up to, so it's slightly random at the moment!