When working as a IT-consultant and a developer you are often called out to check out or fix things for less capable clients. Sometimes this involves watching pretty ugly things.
Not ugly as in ugly people, but as in mind-numbing application-design, ugly code, horrid abuse of APIs and generally 30 year old principles applied to modern technology where these decades-old concerns shouldn't even be an issue. You see stuff you as a professional developer find revolting. Ugly things.
When you during a day at work find yourself in the worst amateur Italian-style spaghetti-code, it's easy to lose faith. It's easy to curse your job. But then people show you stuff like this and this. Yes. This is code. They are so called regular expressions.
Regular expressions are extremely powerful and can do almost anything more efficiently than regular structured code, however the potential for abuse is enormous, not to mention the obvious readability concerns. So when I look at the horrid stuff I sometimes encounter in my job, I thank the Gods that as few people as possible know about these things.
I can't imagine the crap I'd have to wade trough then :P