Pain sensitivity can depend on where the pain is. I think I have an average pain threshold for most things, but cardiac pain has much less effect on me than usual. When I had a heart attack and did a stress test on a treadmill, the staff said I should have been curled up on the floor moaning, given what the ECG said - I just felt very tired with a slight ache. Apparently this kind of insensitivity is more likely if you're diabetic or female - they weren't expecting me to have it.