I'm not a professional software developer I mostly program for fun, so i'm not sure how valid my opinion is but writing my own virtual machine, simple assembly

I'm not a professional software developer I mostly program for fun, so i'm not sure how valid my opinion is but writing my own virtual machine, simple assembly language and two pass assembler probably taught me more about fundamental computer concepts, managing a not too large but still decently sized programming project, different hardware architectures and ways that can be structured and general low level programming concepts than any book i've read or other project i've worked on.