Ever stumble across one of those functions? The little helpers someone wrote forever ago that accomplish exactly the thing you're trying to do (and probably just did)?
"Where did this come from?" you ask yourself, "Why did no one tell me about this? ... do they know about it?"
And then you poke around a bit, and you find out that not only is it widely known, but also used everywhere.
They're the tools too specific to come up in a beginners tutorial, but too widely-used to get more than a passing mention in the advanced ones. You've probably heard of some of these, but you might still have a gem or two to discover.
Video URL: https://vimeo.com/144831200