Scabs are the leftover remnants of your old skin. If you love to eat that stuff, you'll have no problem eating sushi.

Nasty story...sorry. When we were 15 or so we worked at a major fast food chain. One day a customer was really complaining about his burger, after bringing it back twice, asking why us morons couldn't figure out how to add enough bacon to his burger. Well one of the dudes in the back was particularly offended. He had this huge scab on his leg that was about the fall off. He picked it off and put it underneath one of those circular peices of bacon and threw it on the burger, and then handed it to the customer with a smile, and watched him eat it.

There is always that one twisted kid that eats his scabs. (gag)