A sweet YA dark comedy about mental illness, this book was definitely worth reading, though I don't know that I'd re-read it or add it to any of my shelves. It isn't really a wonderful book that just fell shy of landing on my favorite list, or a favorite, or a bad book, it's just simply A NICE read. 
 If you're a fan of Calvin and Hobbes, as I am, you'll find a lot of allusions to the original work which should keep you happily reading, but once you've shared it with all your fellow Calvin and Hobbes fan friends, you might very well forget about it for a while. 
 It's cute, at times sad, but nothing outstanding. 
 Now to be fair, I should mention that it takes A LOT for a straight up contemporary YA to stick with me. I personally prefer sci-fi or fantasy stories or even just a bit of bizarre speculative fiction to run of the mill stories about normal, unmagical people. And I kind of got over my "problem kid/issue YA" novel phase very early in life... I mean, overall, if I want that kind of thing I could just watch whatever Lifetime movie has been posted to youtube lately. 
 There are rare exceptions, such as Tiger Eyes, Speak, even (to a much lesser extent, though I did enjoy it) Choke, but it typically isn't my genre and I probably wouldn't have even read "Calvin" if it was just about a mentally ill boy walking across a lake without the Calvin and Hobbes stuff thrown in there. 
 I think the fact that the writing is very basic is a bit of a turn off for me. I fully realize that this was meant to read like a teen boy's fan letter/English project but I did find it a bit too simplistic even so at times. 
 Still a nice book, though.