I needed to first get the willingness to change my previous ideas of what I really needed to take when backpacking. That was the first step on the road to Ultralight backpacking. Reading about the experiences of others with Ultralight backpacking and talking to other backpackers offers a tremendous resource for gathering information that can assist in reducing ones backpack weight.
Look in a mirror the answer is hanging on your back ;-)
Michael's Ultralight Backpacking Page
Gore-tex rain gear: I heat up to much when hiking wearing gore-tex material.
Leather or fabric boots: When I carried a heavier backpack they were useful. Now that I have pared down the weight of the backpack weight they aren't neccessary for me.
Michael's Ultralight Backpacking Page
Talking with other hikers on the trail and off the trail asking them, "what don't you like about this piece of equipment". I've found asking that question to be very helpful in determining whether to consider that piece of equipment or not.
For me it allows the ability to relax while backpacking as I'm not carrying a burdening weight on my back. I can hike those 10-15 miles during a day and not be worn out do to heavy backpack weight. Being tired from a days hike is acceptable. Being tired from a days hike carrying a heavy backpack isn't acceptable any more. For myself I've found the enjoyment of hiking in trail running shoes, glorified sneakers, since I pared down my backpacking weight. I no longer stomp through the woods in heavy boots with backpack in tow. I almost lightly walk through the woods, well not that lightly, and enjoy the trail even more. In rocky terrain I can easily and almost effortlessly step over the obstacle in my path.
During the heat of the summer I'm usually drained at days end from any hike. I recover more quickly now that I carry a lighter backpack. A short rest period some cool water and a snack and I'm able to enjoy the remainder of the day refreshed.
During cold weather hikes I'm able to walking faster in the begining of the hike to warm me up and not become drained from the exertion of lugging a heavy backpack. Once warmed up I return to my normal hiking style and remain warm until I take a break or finish the hike for the day.
I enjoy the feeling of removing my pack during rest stops or at the end of the day and not feel like the weight of the world has been lifted from me. When I carried a heavier backpack I felt like I was floating when I took off my backpack. I literally felt the need to anchor myself to a tree so I wouldn't float away. For me I'm glad I don't have to experience this feeling any more.
Probably never.