It is delusional to believe in fairys.
Steve has been on a lot of medications, and while he was out, he thinks something rearranged furniture in his house.
Steve wants to think about who or what did it.
Steve thinks that he's seeing things simply because he's been on so many weird medications lately, and tells his friends.
Steve thinks that a bunch of faeries broke into his house and rearranged his furniture, he tells his friends this.
His friends tell him to see if he can get the medication adjusted, and want to help him.
His friends laugh at him and think he's gone off the deep end.