Sometimes, Remus Lupin could not believe his luck.
Exactly one month ago, before the start of his seventh year at Hogwarts, he had been damn near miserable. There was no one, particular thing that was bothering him. It was a lot of things—or rather, an absence of a lot of things—which contributed to his generally sour disposition. The previous summer had been especially awful. He had taken a part-time job at a Muggle book-shop to earn some extra money and keep busy during the vacation. Apparently, however, people don't read during the summer. He ran the register from mid-day to close, five days a week, and it never ceased to amaze him how empty the shop remained all the while. Needless to say, Remus had a lot of time to himself that summer.
When he was working, Remus was very often left alone with his thoughts. He would read the occasional book, of course, but even that got old after a while. Every now and then he would write a letter to one of his friends, but he figured that they were probably busy doing normal teenager-during-summer-holiday things, and he couldn't bring himself to bother them too often with painfully boring accounts of his monotonous work days.
Therefore, Remus spend the majority of his summer thinking. Pondering. Remembering. Trying to make sense of the past six years of his life, in anticipation for the most important year and, hopefully, his best year yet. Some time toward the end of August, when the days were long and nights at the shop were particularly unbearable, Remus Lupin made the most important decision of his entire life thus far. Now, it was only a matter of setting his plan into action.
And if he had known how much could happen in one month, he would have done something like this a lot sooner.