I stretched my ears about 6 years ago. It hurt me more than any tattoo I have on my body. My ears are at a zero gauge, and at the most, I would go up one more size to a double zero. All of the people (men, actually) that I've talked to about stretching ears insist that it didn't hurt them like it hurt me. Each time it felt like someone was holding a lit match to the tendon that runs from behind my earlobe down my neck.
My only conclusion, aside from the obvious (that men are fucking liars) is scar tissue.
I pierced my ears at the mall when I was ten, and these guys had their ears stretched right after they were pierced for the first time. Maybe scar tissue is more tender than normal skin... Which leads me to believe that your first heartbreak hurts, but not nearly as much as the second, or fifth.
I think once the heart is covered in repaired tissue, it hurts that much more when it's torn. Wouldn't you think it would hurt less? Like calloused hands? When people get hurt, they tend to do one of two things. Either they receed into themselves and become less apt to be hurt again, never putting themselves out there anymore, or, like a stupid dog, they keep doing the same old things and wonder why they keep getting kicked. They never learn. I am one of these dogs. No amount of kicking changes my behavior. And I hate that I put myself out there again and again and expect a different outcome. It's not smart, but it's how I am, and no amount of pain will change that.