I followed alone fairly well for the first half of the book but I won't pretend to understand all of it. I remember a lot of the concepts from high school and previous personal research. 
 Not only does he give a very good and understandable overview of multiple theories and concepts, Mr. Hawking also shows the evolution of how mankind understanding evolved. He shows how individual scientists came up with their theories, removing the mystery and making them relatable. Even when, or if already, some concepts become out dated this aspect of the book while remain relevant. 
 Topic covers of Theory of gravity, theory of relativity, chaos theory, quantum theory, string theory, the quest for the theory of everything, and more. 
 Relatively easy to read and surprisingly funny at times. It enough to peak your interest so you'll want to research more. Written at a level that the average person can understand the general ideas but requires you to stay focused. Recommend for anyone with a mild curiosity on mentioned topics and physics in general.