I think it's strange that, as far as we know (and we've looked) Sawyer didn't have any marks before he came to the island, in spite of the rough life he led. The island inflicts scars one after the other. And I just got intrigued with the idea that if he were ever unintentionally bruised, he'd be bruised in the way that Jack intentionally "bruised" himself. I think Sawyer thinks they're connected like that, though he'd never say so. Thank you for reading this! :)