[omnicognate]

I have some basics down pat (., +, *, ?, ^, $, [], [^], (), \d) and anything more I always have to look up (and much of it differs between engines anyway). Usually, though, what takes more time to figure out than the regex itself is whatever unholy combination of escaping rules is in force in the place where I have to use it.

[brainwipe]

I'm with you - if I'm doing a quick find/replace in VSCode then I can usually muddle a way through but anything more complex leaves me somewhat at a loss.