When I realized that I haven't in fact completed the binding of Isaac all the way through and I still have to beat the last boss, satin. So I have to go through the whole thing again, kill all the bosses, mom, moms heart, then finally get to satin. And if I die I have to start again. Pretty big disappointment since I was proud of the fact I had beaten the game since its incredibly difficult but it turns out i was wrong. Come see me in a few days it'll get done .