Title: Seriousness. Sentence 1: Charles was a very serious man and didn't laugh a lot. Sentence 2: His friends tried to tell jokes but he remained untouched. Sentence 3: To make him lose his composure, his friends decided to trick him. Sentence 4: They invited him to a conference which was in a fact a clown party.
When I came back in, I couldn't enjoy the trip anymore.