From what I have gathered, he has spent most of his summer getting closer to his Godfather. It was heartening to know that he was finally feeling that familial love that he had been missing for so long. It also seemed that Sirius took his recovery more seriously after my threat. Knowing the effects that dementors could have on a person, it was good that he was doing so. Without proper care, having any loss of your being causes unwanted changes. To say you could become crazy was a small symptom of what could truly happen.