This is going to sound weird, but could I get some other autistic folks to describe to me how you feel when someone else is in pain or otherwise suffering, and conversely, how you feel when someone else is very happy? Assume the other person is autistic, and that you have no direct knowledge of what is making them feel that way.
personal, 'experience of suffering'
@diligentcircle I tend to very strongly experience 'second-hand suffering', seemingly much more strongly than most people, whether or not I know the cause - whether the other person is autistic also doesn't change that, it even happens for people whose suffering I merely hear of and whom I've never talked to personally.