https://www.cloudsavvyit.com/921/how-do-you-actually-use-regex/
regular expressions are used to automate things related to text
https://www.cloudsavvyit.com/921/how-do-you-actually-use-regex/
Jokes
when you fix a problem with regex, you now have two problems
there are many explanations for this, one is you are parsing text, and one day someone will break it by chaning the text upstream
then you might be trying to fix some long regex filter which is hard to read, they look like this
(2|6|a)\d{4-5}.*(?>$(a(a-z)\W\s)\\/\*$
or worse and if you didn't write good specs and docs you will likely spend more time fixing it than it took to originally build