I'm actually with the others on this. I've been looking at CompSci papers, engineering methodologies, and real world code going back a long time. I saw a few patterns in use like Parnas' information hiding or state machines. I didn't see GoF patterns until I saw Java people using them while recommending the book. Also, many people in industry forgot about prior methodologies that got results without over-abstraction such as Cleanroom but were all over GoF patterns and latter Agile methodology. It seems their work was pretty influential.