I think this book is overrated. The Author did a really hard work and wrote every possible thing in the world and 5 star for that too. but the real problems are
1. This is not for beginners
2. This is not for intermediates.
3. This is for Advanced Programmers only, and only if there are some more content related to it over the internet.
4. Singleton is simplest concept, but this 2nd chapter proves its the hardest possible thing.
5. The Example used may or might be real worlds, but the concept is lesser focused than the examples.
6. We are learning the Builder pattern, but the interfaces and all other extra stuff proves that Pattern is not important but author is more intelligent than you (even though he used bad examples, rubbish interface including)
7. Abstract factory method tell the thing in 2 pages, but to show off english it stretched too long.
Main concept must be there before going on real world's examples, including too much interfaces and nesting inheritance. We all here know that complex implementations, a junior developer can write those relationships far longer.
After reading builder patterns chapter I made sure that it will be time waste until I have 20 years of experience or on death bed to really be able to read this book.
Lastly I would say, before reading it, go to chat gpt and ask it nicely "would you please teach me design patterns of programming" or any promot you like. Your brain and mind indexing/hashing needs to be trained to figure and implement those features (not memory with theory)