Here's another trick that's helped me a lot over the years: open up your favorite library on Github, go back to the very first commit and start reading, commit

Here's another trick that's helped me a lot over the years: open up your favorite library on Github, go back to the very first commit and start reading, commit by commit. If you don't understand something, just copy the difficult section, line by line, on a repl, inspecting variables and/or function results.