As someone who also just wrote toy compilers/interpreters: I think it is a valuable thing to just dive into a subject that quite obviously interests you so muc

As someone who also just wrote toy compilers/interpreters: I think it is a valuable thing to just dive into a subject that quite obviously interests you so much as long as you are humble about it. At some point you change/tweak/break something. Then your humble instinct will say: "I bet this is a common problem, let me research it". And so you get deeper understanding of what you do in a fun and tangible way. If that at some point means you get to read PLT about type theory and formal semantics, then so be it. But at this point you'll know much more about the 'why' and can assess/relativize the purpose, importance and relevance of a particular subject.