I think many of us can. I generally ask for some means to calibrate their pain scale to my understanding so that I can adequately answer the question.

For example, where does bone-on-bone grinding/disintegration fall on it.
Having one's leg crushed between to vehicles, one stationary and the other in reverse.
Being hit int he face hard enough to dislodge a tooth...

Then I tell them my ratings for those three things: 7, 8, 3