[ggm]

Your examples use * and $ and + before they are explained. Inductive learning goes smoother if new concepts have context.

You explain [^ ...] So the use of these examples without explanation is .. unexpected. If you use examples which don't depend on * or + or $ I agree it's 'boring' but for a class of learner these surprise moments interfere with learning.

You only casually mention capitalised \thing is inversion of \thing \d and \D I think you would want to repeat that \w and \W and \s and \S and after three.. it's established.

I see this a lot in e.g. Haskell tutorials: simple inductive constructive learning examples littered with 'oh I explain that later just ignore it for now' syntactic constructs.

\( and \) are dangerous in substitution. Their meaning shifts from regex to variable-marker. Surely this needs to be noted in passing?