Reusable, reliable solutions that we face everyday in software development.
One is always tasked with a hurdle to solve a recurring problem over and over again, where we (the developers) challange ourselves to solve the problem once and for all, aka the solution. Therefore, the primary goal of design patterns are to encourage programming efficiency and code reuse.
If you find your solution to work time and time again, it is safe to share, evangelise, and document your solution and make it official.