Sunday Library Secrets

I read PostSecret just about every Sunday. The site collects secrets mailed in on postcards, posting a few and publishing others in a series of books. It's a glimpse into the not-always-awesome corners of people's minds. Some posts are wonderful; some are disturbing, so read at your own risk. And it's occasionally not safe to be viewed around children or at work, so be warned.

In any case, this Sunday there were some secrets involving libraries:

On the back of the last one it says, "I hope this inspires people to do the same".

Is there a site to look up what sort of book would be categorized under a specific Dewey number? I get that the 150s are Psychology, but the most I can get from that is that the image's file name mentions burnout.