I've been playing with Perl (where playing I guess is the operative word) for about 6 years now.
That means I've read -- or tried to read -- what have been rated as some of the best books on Perl. But I've read them intermittently, as I do all technical works: a bit here, a bit there, pause a bit, try a bit of code, look up a chapter... etc.
This book was different. Within 12 hours of getting it, I had read continuously through to the end of Chapter 7 (120+ pages), taking it all in voraciously. Somehow, this has picked up on every important cranny in the language I had skipped over as "too hard" or "too confusing" -- with all deference to Larry, Tom and Randal.. It hits the spot with examples just where I need them, and with concepts and analogies that clicked into place beautifully.
If you know about pointers, but puzzle about refs and typeglobs and $$this and \$that and *somethingelse, if talk of aliases, closures, and variable suicide have made you feel inadequate... if the works of modules, objects and stuff like that still has you confused, this book is for you.
The only problem: I used to think of myself as a tech writer... they still pay me for it. Now I just feel inadequate. But I'm learning.