One very important thing missing from this primer is that Make targets are not 'mini-scripts', even though they look like it. Every line is 'its own script' in its own subshell - state is not passed between lines.

Make is scary because it's arcane and contains a lot of gotcha rules. I avoided learning Make for a long time. I'm glad I did learn it in the end, though I wouldn't call myself properly fluent in it yet. But there are a ton of gotchas and historical artifacts in Make.