It is because, for each problem/annoyance you have, there are certanly many other people in the world who have it too. In addition, many of them are exposed to

It is because, for each problem/annoyance you have, there are certanly many other people in the world who have it too. In addition, many of them are exposed to a similar environment so it is probable that they come up with similar solutions. Anyway, it doesn't matter how many are they, but how many have the will to make it happen. That is what makes all the difference.