[meowface]

Don't know why you're being downvoted. Of course this is all anecdotal and armchair psychology/psychiatry/neuroscience/neuropharmacology, but there could plausibly be some kind of correlation, here, and every anecdote adds to the discussion, even if of course they shouldn't be taken as empirical support for the hypothesis.

I've seen research about how opiates seem to reduce perception of both physical and emotional pain, which may partly explain why some people in unfortunate situations may become addicted. Emotional pain isn't adjacent to empathy but isn't necessarily orthogonal, either. If there's anything to this, it makes me wonder if there could also be some correlation between opioid receptors and empathy, or even some sort of correlation between pain and emotions in general.

[jrumbut]

While we're talking anecdata, for the first ~30 years of my life I found absolutely no relief from acetaminophen for anything from illness to injury to random headaches.

A couple years ago my wife cajoled me to try taking it again, and I went from bed ridden to feeling poorly but able to function. Not a miracle cure but really helpful a few times a year. Is there any known association of age and acetaminophen effectiveness?