The quickest way to build a boat to cross the river, is to cross the river without building a boat.
Sometimes we get so caught up in building the boat that we forget to check if there's a way to cross the river without it. And if there is (and more often than we think, there is), we can save oodles of time, resources, and work. And, being on the other side so much sooner, we can do many more things, and things more worthwhile.
As a concrete example, suppose you wish to write a program that takes two images as input, finds similar parts of objects, and circles those common features on each image. You set out to sketch how such a program would work, formulate algorithms, start building prototypes. Or, you could do a little "Googling" to find that this is a well-know problem called feature matching, and is already solved by the commercial-friendly, open-source OpenCV library.