[21echoes]

This seems to be exactly the definition given in the article?

[bhauer]

My read of the article was quite different. Namely, "Imagine you had to shave a yak. There would be a lot of things involved in getting that done, many of which you don't know ahead of time."

Ultimately the same underlying meaning, but quite a different illustrative scenario.

[QuercusMax]

Yes, your goal isn't to shave a yak, it's to do something else, but you have endless side quests including being a yak barber.