While earning my degree in Mechanical Engineering, I was constantly bombarded by all kinds of systems. Thinking in systems is a critical part of many areas of engineering. Whether you are looking at an electrical circuit, an ecosystem, HVAC, pot roast or a nuclear reactor, there are many similarities in behavior and structure. Thinking in Systems by Donella Meadows does a great job demonstrating the purpose and approach of mapping everything and anything to a logical system.
The first half of the book introduces the reader gently to the basics of what a system is and how they are defined. You'll learn about feedback loops, flows and stocks. I found this section repetitive, basic and boring. However, if you haven't had this stuff drilled into your head for four years, it may have more to offer you.
The second half of the book I found incredibly informative and interesting. The author departs from an engineering perspective here and you'll see less and less charts and diagrams at this point. Chapters five and six discuss common reasons why systems fail and how to help them succeed. There are some quirky assumptions we seem to erroneously make over and over. The author is kind enough to lay them out plainly so you don't fall victim to the same mistakes (though you surely will).
The real joy of this book is the reason I wanted to become an engineer: it helps you understand more about the world around you. Thinking in Systems can apply to just about anything. It's a pretty powerful concept that could help you more logically organize your problem solving at work or home. This book only offers a basic introduction, but even with a degree in a related science, I still learned a lot (mostly in chapters 5 and 6). If you do pick it up and enjoy it, I'd recommend checking out some (slightly) more technical offering that delve into a wider range of systems modeling with higher math.