This is a fairly in-depth examination of the Wall and the archaeology done around it to try and understand what it was used for and at what times. As such, it’s a lot of information that most people wouldn’t expect to hold in their heads after, unless they’re deeply interested in the topic. Which is pretty much exactly why I read this, back during my exam period. I really love reading books like this that sift through the archaeology, present possible conclusions and discuss what is most likely. I don’t expect to remember this or that about the forts — no one expects me to remember it — but all the same I learned about the Romans and the British of the period, and got to connect some dots in what I know.
It’s perhaps not the most scintillating reading if you’re not pretty engaged and interested in the topic, but it’s interesting stuff and they make a good case for their ideas.