Mr. Colello is a Su-Genius. I use to think that people doing these puzzles were geeks or "squares" (no pun intended). That is, I use to think that before I picked up Colello's book and actually did one. I'll admit the first one took a while, but once i started i couldn't put it down. His puzzles are addictive. The different levels of experience that Colello has lets you know when when you have reached the next stage; and let me tell you what a great feeling that is. All I have to ask is, when will Volume 2 come out? With Colello's book in hand, it's hip to be square!