Unpopular opinion, but I think the Design Pattern book created more problems than it solved. It encouraged people to come up with clever designs for object-oriented systems. Object-oriented systems themselves tend to get too complicated. And then making people think they have to use some kind of smart design encourages an addition of complexity.
The first rule of design should be make it as simple as possible. And this book, I think, does the opposite for many people.
The first rule of design should be make it as simple as possible. And this book, I think, does the opposite for many people.