Piper: "In fact, a 15 pound or so load doesn't really tire me out at all compared to no load at all…I think it would be awesome to be able to do a backpack trip with only 5lbs of gear…"
It's funny how we can reach a point that we don't really care about the weight any more, but still want less!
When my pack weight hits the low 20s, it's the same as having no pack at all. Getting it any lighter isn't going to make me any faster. With the warm weather here, I'm carrying <12lbs on my almost weekly 1-2 nighters, so it just doesn't matter.
That stuff really "added down" when it meant a sub-30lb pack weight on day 1 for a week in the mountains last fall, though!
A couple of decades plus a lot injuries past my prime, 30+ miles in a day with even an ultralight pack is nothing more than a fantasy, but all day comfort on the trail AND all night comfort in camp is a pretty sweet combo.