You are one of the lucky few. Right after I sold my iBook G4 1.2 to my old room mate, he had nothing but problems with it. Later on after the warranty finished, the HD died again (applecare fixed it the first time at the 1.2 year mark).
Most of the iBooks I have seen have not served their owners well. I did pickup one which still ran but looked like crap. It had scratches on the screen, bad keyboard, and bent hinge...yet it still booted no problem.
I guess there is always a few out there that will keep on going.