The cheat sheets exist because people aren’t learning regex. You don’t need to learn every flavor of regex, just the one or small number you need to know. And once you know the basics, the differences are very minor.
The basic regex is easy, infact an English word is a regex! A dot matches a single character. Star multiple of the previous character. Just that is useful for a lot of cases!
If you believe it is possible to become an expert in regular expressions as they exist in modern computer languages in "a couple of hours at best" you are delusional.
