Well now we have introduced a differential that being a difference between pain and discomfort. I'm not sure where that line is drawn other that to clarify, I don't mean pain in the sense of being caused by injury, meaning pain that requires healing over the course of days following a ride. But it CAN mean pain caused by a previous injury or other influence such as arthritis.
And so I guess that would be "discomfort" experienced on a long ride. I have to be careful about posture or my neck hurts (it's hurting right now at this computer) Actually there is some level of pain in my neck almost all the time. Riding long distances just exacerbates it. Same with lower back.
And so, I'm at a stage in life where the pain, discomfort, however you want to categorize it, can cause me to head to the house before I'm out of steam. I haven't ridden a Century since 2015 and right now, I don't think it would be possible for me to ride a Century, even though I've ridden two metrics in the past month.

And so my questions were intended to clarify a couple things to me, one being, SHOULD we expect to experience pain while riding (and at what point), and whether I'm an anomaly because I experience pain, or just "normal" and at my age(57), I just have to expect it. I can live with that, I live with some level of pain every day. I much prefer riding and, pain be damned, just staying active because I know the alternative isn't attractive.
But I do have to wonder though about those who claim no pain, especially on long rides at our ages.