Sometimes you face a problem with the feeling that someone must have solved it before. There ought to be a thing that you can buy that will solve this, but your thorough investigation comes up with nothing. Then you have to solve it yourself.
Then you realize that the next person who is facing the same problem will do the same thing. That's why we try to make those solution we feel are general enough and into products. This is where we collect our ready-made solutions. We will add more as we go along.