Southbound, you must have really good genes and higher Test. Plus are taking good care of yourself. I bet you have a hairy chest too.
Not all men who slow down are over weight though, mine weighs only 150, he eats very good. I compare his chest to a "Charly Brown Christmas tree" - a sign of lower test guy. All about the hormone for many many men , what God blessed you with- though no fault of your own, or your wives.
Plus if men have built up resentment over time, loose attraction for their spouses, getting used to not getting it & suppressing it/stuffing it down, I would imagine these things can slow a guy down too. Many claim the "Use it or Loose it' philosophy when it comes to sexual potency, even hardness, got to keep the blood flowing ! These things need exercised too.
I told my husband I think I am making myself look bad on this forum with all my "draining him" talk. He assured me tonight he would do it like "bunny rabbits a couple times a day" if he could, the desire is always there , every day is good, so long as it goes up, he WANTS to use it. He has told me this many times. Still love hearing it though.