Self Improvement or Something to Hide?

I was on the train yesterday evening and once again everyone beat me to a seat. I found a pole to grab on to dear life and proceeded to play solitaire, as i looked up I noticed this girl was reading a book. I usually like to see what people are reading these days, and maybe add to my Summer reading list. The book she was reading had an interesting title " How to Gain Friends and Influence People". I thought to myself do these books actually work. I mean I see so many self-help books out there but they all get lost in the sea of so many others.
She seemed to be really into this book with all the high lighting and note taking between the margins. The funny thing is when she saw one of her friends, I suppose and old friend, she immediately put the book away as if she was embarrassed about it. It made me think do we really know who are friends are, do they have hidden lives or issues that they are to embarrassed to admit. I also thought about what Prof. Henken spoke about in class, how everyone portrays a certain identity with certain people. I just thought it was really interesting.