At the time when I read this book I was in my "John Green phase". I think all girls (and maybe a few boys) go through one of those. 
 I liked the subject, to be honest, and I pretty much liked Colin, but this book wasn't for me. Definitely. 
 Well, it's impossible to have had 19 girlfriends named Katherine, right? Don't get me wrong, I'm totally a fan of weird books, but this is not just weird...it's impossible. Katherine is a common name, I agree, but seriously? This was, like, the guy's criterion in choosing a girlfriend? I didn't get that part. 
 Colin and Lindsay were interesting kids, but they were very much like the other characters in Green's books. Smart? Outcasts? Odd parents? 'Oh so' perfect for each other? Yup, just like Q and Margo, just like Alaska and Pudge, just like Duke and Tobin (for those who've read "Cheertastic Christmas Miracle). I spy with my little eye...lack of ideas! 
 But I liked the ending. No, not because the book was over, but because it was pretty original. Colin finally had his "Evrika moment".