GoForSmoke:
What part of "some chips/systems" is stumping you?
I assume you are taking exception to the text I quoted rather than what I wrote. In that case I will respond more directly to the quote... Some non-compliant C++ compilers used for some chips/systems may not correctly cast a true to 1. We don't care about those chips/systems. The compiler used for Arduino is a compilant C++ compiler so true is guarenteed to cast to 1.
if (-1) Serial.println( "-1 is TRUE" );
What does that have to do with casting a bool[ean] value?