3 days was the time that took to Sirius to face the reality. For 3 days Sirius waited for James. 3 days after, on his birthday, Sirius finally accepted that James wouldn’t come. Sirius would not celebrate his birthday with his friends. James was dead. They are gone. He was alone. “Happy birthday to me” was what scaped his lips before the crying became so strong that he felt that he could not breath. He was alone.