Was he so nostalgic for the smell of fresh morning black mud or did he have other motivations? The question people usually ask is: How Sirius Black escaped from Azkaban prison? And even more importantly, how did he manage to stay sane?
We know well enough that the Dementors perform their kiss on the prisoners and take away their every happy thought. This is how Death Eaters kept their “sanity” while incarcerated there, like Bellatrix Lestrange for example.
Since it is reasonable to assume most of the thoughts in Bellatrix’s mind are evil, she kept most of her personality while incarcerated. But she was still pretty damaged when Voldemort freed her. The books make no mention of this, but the movies did try to put an emphasis on this.
So, why didn’t Black lose his happiness and sanity in Azkaban?
When Sirius is reunited with Harry, after the whole ordeal with Peter at the Shrieking Shack, they have a few brief moments. Sirius explains how and why he kept most of his sanity.
An excerpt from the book
“I don’t know how I did it,” he said slowly. “I think the only reason I never lost my mind is that I knew I was innocent. That wasn’t a happy thought, so the Dementors couldn’t suck it out of me… but it kept me sane and knowing who I am… helped me keep my powers… so when it all became… too much… I could transform in my cell… become a dog. Dementors can’t see, you know…” He swallowed. “They feel their way toward people by feeding off their emotions…
-Taken from the book Harry Potter and the Prisoner of Azkaban
There isn’t a precise formula for surviving Azkaban, as Sirius’ testimony suggests. However, if one has strong drive and motivation to endure the torments there, they can keep a reasonable amount of their sanity.
As for the part where he escaped by transforming into a Black dog, we know that Sirius was an unregistered animagus. This explains why no precautions were put there to prevent him from abusing his animal form.
Why didn’t Sirius escape Azkaban earlier?
This question is also frequently used as a plot hole argument, and it does hold some merit at first glance. Why wouldn’t anyone use any ability they have to escape such terrible torment? But, while it is fairly asked, it excludes a vital part of the puzzle.
Those fans who pointed out this potential plot hole forget that Sirius Black is indirectly responsible for the death of James and Lily Potter, his closest friends. In fact, he probably blamed himself more than the killer.
It is never stated explicitly, but it is possible Sirius didn’t want to escape or didn’t care at all about what would happen to him after that. He was the secret keeper for the location of the Potters, but expecting that Voldemort would know this, Sirius suggested that the secret be entrusted to Peter Pettigrew. And we know how that went.
Sirius was a broken man emotionally even before Azkaban
Sirius probably didn’t even try to argue his innocence and tell anyone what actually happened because he was in total shock. This was followed by complete depression and loss of the will to live, which explains why Sirius never argued his case.
He didn’t even tell Remus, or Dumbledore, or any of his friends from the Order of the Phoenix about what actually happened. This is all speculation of course, but it perhaps explains why a man would willingly go through such torment.
Sirius was proud and even cocky in school. But, in his heart, he loved his friends more than anything. For a guy like that to learn that he made such a mistake that it took the lives of his best friend and his wife would be nothing short of devastating. He may even contemplate suicide.
For someone proud and cocky, learning that he was so wrong would probably mean he would want whatever punishment came. He would welcome it, and Sirius probably did. But, as we know, once he learned that Peter is on the move and Harry is in danger, his will to live returns.
Harry Potter and the Prisoner of Azkaban story perhaps hides many more layers than it initially appears. It is a book about friendship, the pain of loss, and the will to pick up the pieces and move on. These motifs are often encountered throughout the entire series and are a big part of the Harry Potter story.