Lifting 150 pounds feels heavier for a strong person than lifting 50 pounds does for someone 1/3 as strong....On the contrary, I should have stuck right there with skeletal loads and soft tissue strain. That nicely explains the phenomenon. If you could train your muscles to bench press 2500 pounds - which I suppose is theoretically possible - you'd be stressing tendons and bones to the point where you'd likely do them harm. Muscles can be trained, but the other structures not so much. Hence the sensation of greater load even as training makes the hoisting easier.
Before making theories about things like skeletal loads and soft tissue strain, let's look at some other phenomena....
The same is true for smarter people doing trickier calculations, or more creative people solving harder problems. Ease scales proportionally, yet the absolute difficulty still fully registers - and even weighs, in an undefinable way - above/beyond relative levels of capacity/ability.A more powerful computer will solve a difficult problem more quickly, but it generates the same heat to do so, regardless of hardware power. So while a task might be accomplished with greater relative ease, the absolute difficulty remains easily measurable. While the mind's obviously not a computer, there are surely analogs - unavoidable side-effects and overheads which accompany increased neurological loads. As with the weight lifting observation (See? I knew they were related!), certain capacities scale, while others don't, and the latter account for the spidey sense re: absolute exertion.
If you're in a lot of pain and taking a lot of painkillers, and the pain even slightly exceeds the medicine, that slight marginal pain seems somehow more burdensome - even if not more quantifiably severe - than moderate pain seems without painkillers.If you're experiencing enough pain to be on painkillers, you're surely sensitized to that particular pain, making even a mere twinge quite unpleasant.
If you have great equanimity, and something enormously irritating punctures it to just barely tick you off, the full magnitude registers despite the mild triggering.As you develop equanimity (e.g. via meditation), you lose some stoic backbone, simply from disuse. Wafting in a state of graceful serenity, when stress does poke through, it feels more distressing than the everyday plume of strife experienced by less composed folks. So this is another matter of sensitization. See this interesting posting explaining how habitually warm people suffer when they catch a rare chill, and how highly creative/resourceful people can be paralyzed by obstruction, and how "I have no facility whatsoever for operating talentlessly in realms in which I'm talented."
The heat of a 95 degree day in a 70 degree air conditioned environment is more onerous than the heat of a 80 degree day without air conditioning.The air conditioning itself - yielding unnatural humidity and recirculated staleness - probably accounts for this.
Well, the whole thing didn't exactly crumble to nothing. There were still a couple interesting insights to be gained...