We all got the impression that Sirius was not exactly himself after Askaban right ? We see it again and again from the slashed portrait , the cut curtains because he could concive that the Rat was not exactly were he was expecting him to be or the simple fact that he forgot when the full moon was coming and maybie even it's connection to Lupin when he decided to bring Pedigrew and James son into the shack that night , to have a bloody reunion . Those night were important to him and yet he allowed himself to forget such an important detail ! He was many things but fine was not one of them ... Am I the only one thinking that considering all of this and with how much joy he jumps on the memory train of nearly killin Snape and getting away with it as soon as he meets Lupin after years , even forgetting that he was there to take revenge for a moment , that the slyderins were in true and real danger of him that whole year ? Some of these kids no matter if they had even been alive during the war were children of Death Eaters ... in my mind there is no doubt that if Sirius meet Draco breaking the rules as kids do , one of the times he was going around the castle using secret passages , he may not even been able to distinguished him from his father for long enough to cause some real damage . And lupin dint know in what state of mind his ex friend was yet he allows him to walk around unmolested ! I kinda see Snape sleeping near the entrance of his house when he wasn't patrolling just in case Black came out to play .
