For some clarification, I'm not trying to imply weight is not a consideration. Absolutely one should not pack what one doesn't need, or what one can't carry. I'm not gonna pack a Coleman propane grill, and a half dozen backup folders, but given a good frameback, I don't count ounces, in as much as, I'm not worried about an extra pair of socks and underwear, or specifically rationing out my trail mix and jerky for only x-amount per day when I can carry the whole bag, or even 1 extra folder + a 5 oz folder in my pocket or even an extra pound for a largish do-all chopper strapped on top of my pack, "just in case".
Trying to find ounces here or there to shave a 35 lb pack down to a 29-30lb pack for a 3 day hike, for me at least, is a non issue, when I know I can carry 40+ without issue. If anything I'll typically trim the wife's load down and add some of her load to my own.
An example of "why": in the military we were doing a 25 mile road March, full gear, roughly 50-60lb packs, when about halfway through our 240 gunner, (a big. 225lb "Tight End" type) was falling behind significantly, his weapon and pack were significantly heavier then mine, an m4 point man, but yet I, who had more of a DB build at around 190 lbs, fell back to meet him, 200 meters or so, and stopped to swap packs and weapons, and still made up the ground to rest of our unit without problems and finished without issue carrying his load; (he slowly made up the ground). Point being, i know my capabilities, as should everybody, as everybody is different, and while I'm not in "as good" of shape as I was back then, I'm far far from out of shape, and I see no need (again, speaking just for me personally), to count ounces here or there, so long as I know the poundage of my pack is well within my range. And i know that even a 40 lb load in a well built frameback is well within my range and causes me little issue to carry on longer treks. My breathing if anything is what causes me the most issue, regardless of weight, because even though i still run 2 milers regularly, and am quite good as controlling my breathing, I'm also still a half a pack a day smoker, (down from years of 1-2 packs a day), which carrying that extra tobacco, again, adds even more weight
