For me it was reading about git internals: https://git-scm.com/book/en/v2/Git-Internals-Plumbing-and-Porcelain https://git-scm.com/book/en/v2/Git-Internals-Plu

For me it was reading about git internals: https://git-scm.com/book/en/v2/Git-Internals-Plumbing-and-Porcelain https://git-scm.com/book/en/v2/Git-Internals-Plumbing-and-Po... It made me understand how simple git really it under the hood, you just need to understand how the commands operate on this simple data structure.