4.17 isn't About Sam so they did not consider him and demon blood withdrawal during those three weeks but i think that he spends nights shivering cursing the (perfectly functioning) heater in his shitty apartment and throwing up in the toilet and that amongst all his "i feel wrong this isn't meant to be my life" is a longing for the taste of iron between his teeth and i think that the day before he quits his job sam wesson meets a dark-haired woman at a bar who he swears he recognizes from his dreams and back at her motel room she hands him an opaque glass and says "i've put something in your drink. wanna try?" and he does. and when zachariah restores sam's memories at the same time as dean's sam doesn't get an angel to explain what happened to him he just hears ruby sitting on his mattress beside him take a breath and say "you're back." and she leaves before he can process anything and he's left with this hunger and his phone ringing in his pocket