Can't judge a book by it's cover, unless that book is reading a book, thus allowing judgement of former book by said cover of latter book.

Remember Allistair Winslow Thurston-Sackville? The pale, simple Victorian child-headed chap from the train. I saw him again this morning reading a book! I was so excited. Finally, some illumination on the essence of this strange person. As he was holding the book and reading, I could only see a partial title at first. I saw "Dict..." Dictionary, I deduced, must be a dictionary. Dictionary of Simple Phrases for the Man-Child? Dictionary of Commonly Used Words for Asking Mommy to Make a Jam Sandwich? What could it be???

I watched him concentrating, on the book, almost seeing the information process in his brain. All of his actions and reactions are so slow and deliberate. He blinked and swallowed and raised his eyebrows at intervals, never taking his eyes from the page. I stared at the cover of the book for 8 minutes, waiting for the title to be revealed. There was no bloody way I was going to turn my head for a second and miss seeing it. The rare occasion to get a key into a mystery like this is too precious to screw up.

At last, as we pulled into central station, he closed the book and I saw the title:
Dictatorship as Experience: Toward a Socio-Cultural History of the GDR. What the HELL???

The Google books description is as follows:

A decade after the collapse of communism, this volume presents a historical reflection on the perplexing nature of the East German dictatorship. In contrast to most political rhetoric, it seeks to establish a middle ground between totalitarianism theory, stressing the repressive features of the SED-regime, and apologetics of the socialist experiment, emphasizing the normalcy of daily lives.

Right, so...not what I was expecting. I stand by my assessment of this chap being odd as hell, but I guess he's not as simple-minded as I thought. Can't judge a book by it's cover, or rather, can't judge a man by his bizarre appearance? But can you judge a bizarre man by the cover of his book?