Title: Pokemon Go. Sentence 1: Caleb listened as his friend babbled on about Pokemon. Sentence 2: Caleb told him that he was in his 20's now and didn't care about that. Sentence 3: The next day, Pokemon Go was released. Sentence 4: He was walking to class, when he saw all of his friends in a group.
They told him they were playing Pokemon, and Caleb was left in shock.