Saf is unsure how to tell love from pain. He wonders sometimes, when he is left alone, if he missed some sort of crucial part of having a mother, when he might have learnt to feel love the way other people do. He can see that they experience it different than he does. No one else he knows throws themselves into pain mistaking it for affection.
He has a repertoire of pains felt and analyzed, trying to work out when they were simply pain and not love. He is certain that Bitterblue was some of both. She was his favourite.