Sailed through PPD & PDD thanks to The Amber Book

This is from a message I sent to Michael Ermann, founder of The Amber Book after passing PPD & PDD

"...Despite being more than a little intimidated by starting the ARE in my mid forties, I managed to slog through tests 1,2,3 & 6 in the year and a half leading up to the pandemic.  After a year and a half pause, on a recommendation from a colleague I took a look into The Amber Book and was immediately hooked.  I had been wearily crawling through the Ballast chapters on HVAC systems, learning less in 20 hours than I did watching the 3 part video offered on Youtube.  While I had to watch it a couple of times to completely internalize the concepts, once I did it served as a solid foundation for understanding many of the nuances that separate one type of system from another.  Even more importantly it became obvious, for the first time, just how amazing the compression refrigeration cycle is.  I will never look at a window AC unit in the same way.