Just a few weeks ago I got an absolutely delightful email:

> Ні! This might seem a little out of the blue and it is but a few years ago at a library book sale I got the book "Pi in the Sky". It has your personal library stamp on it, so I guess YOU got it at a library sale and then re-donated it? I had never read anything about math before that was at all interesting and it got me reading lots of other "popular" math books and I got really interested in number theory. I am now a freshman at CMU and planning to be a math major!