Leonard figured he better get back to school, since classes would begin really soon, but then he suddenly wondered if it would be better to skip today. He had no idea where that thought came from. He had never skipped in his life (in his old one or his new one). But for some reason, he felt like skipping today.
Unknown to him, Susan had "placed a spell on him", so to speak. It was just a simple hypnotic suggestion, but it was enough to tweak the person that he would eventually turn into. He wouldn't become a Goth, but he would become more interested in that lifestyle and the people in it. He now had a rebellious streak about him that he wouldn't have had, if Susan hadn't encountered him.
He briefly thought about heading back inside his house, but then decided not. He had had enough of his stupid parents fighting all the time. If there was ever a good reason to bail on his parents, that was it. It was time for Leonard to do what he wanted for a change.
So that was that. He wasn't going to school today.