How do I become that good in debugging stuff like this? I'm guessing he works with gamedev and does this sort of debugging and reverse engineering regularly?
I mostly build free-cameras, which allows you to detach the camera from characters, and for that I had to learn x86 assembly, some disassembler tools and how compilers generally work.
I think it's super rewarding because while you're seeing bits and bytes, and crashes, most of the day, at some point you can see you achieved something by being able to freely move in a restricted world.
I was surprised how far you can get with Cheat Engine. Its disassembler is really good, and you can do injections directly, if you then want to move to your own advanced stuff, you can build frameworks to do all of that using Windows APIs.
By learn to use I mean really do, it's like refactoring tools, it's sort of boring and tiring to learn those, you end skipping large parts because "yeah I already know / it's obvious", then you need one day for an emergency / something right now and feel like you're fighting against it.
For those three (and some others), the key to being very good at it is learning all the small tricks and details, when you don't need it, so the day you do it lets you skip 90% of the work.
As an overall point, I'm sure many people have various different experiences, but for myself while being in high school I needed to parse "replay" files for some games to extract and process information and allow players to post their replays to get stats on web forums, and it helped me to learn a great deal about how to properly reverse engineer and figure out stuff, things that I have no idea how I would have learned otherwise.
Personally I have experience with JetBrains ReSharper for (full) Visual Studio, it has loads of functionality which makes it very fast for me to navigate and refactor even very large C# projects.
JetBrains has different products for many different languages and I expect they offer similar capabilities in each.
Learning all the features at once is impractical, but if you learn a new one every now and again, after a few months or years you become incredibly proficient.
I had a similar experience with conversation macros back in the day when I was a GM for WoW.
You don’t make too many at once as you’ll never remember them all, instead you make them kind of as you need them, which tends to be situations like “this is the third time today I’m writing this long explanation”.
Don't jump in with "hi please teach me" or asking questions in the FAQ/wiki or found easily on the web.
Try to give back to the community (like fixing/improving the FAQ/Wiki) as early as possible.