My theoretical introduction to the world of ultralight backpacking came in the late 1990’s, in the form of Ray Jardine’s, The Pacific Crest Trail Hiker’s Handbook. 
In 2003, I received my practical baptism courtesy of a gentleman by the name of Jim (should have been called John), who hailed from Beaverton, Oregon.
I met Jim on the first day of my Wonderland Trail hike. In addition to being an all-around good bloke, Jim was the first ultralight backpacker I had met in person.
You name it, his pack, shelter, sleeping bag and everything else he was carrying was not only lighter, but considerably more gossamer-like than the equivalents that I was toting around.
“How much lighter you ask?” Probably 60%.
At first I suspected that Jim was some sort of minimalist nutter straight off the commune, but after chatting for a while and thoroughly inspecting all of his gear, it became obvious that the guy knew what he was doing.
From what I could see, he was sacrificing neither performance or safety with any of his gear choices, and the fact that his pack weighed so much less, meant that he was going to have a more enjoyable wilderness experience, simply because he wasn’t burdened with such a heavy load. Rocket science it wasn’t.
It’s funny. After reading Jardine’s book in 1999, I marginally lightened my backpacking load. However, it wasn’t until I met Jim some four years later, that I started to drop some serious pounds from my base weight. Call me Thomas if you like (yes, that is two Biblical references in the space of seven paragraphs), but seeing and experiencing something in person, always seems to resonate more than reading about it in a book or online.
 I found Jardine’s book by accident in an outdoor store in Brisbane, Australia. I was actually looking for a Lonely Planet Guide to “Iceland.” What made this discovery particularly random, was that the fact that “ultralight” backpacking gear was virtually unheard of in Australia at the time. For that matter, so was the Pacific Crest Trail.