In the end, Mr. Wilson was the one to break or "crack up." There was another mentioning of Doctor T.J. Eckleburg, only this time it was not actually him saying or doing anything it was Mr. Wilson's thoughts on him. He saw the empty face on the billboard as God, watching down on them, and seeing Myrtle's infidelity. When Mr. Wilson told Michaelis about this, Michaelis just assumed he was going a little crazy after the loss of his wife, others also saw him as "a little crazy." Which all led him to shoot Gatsby, believing that Gatsby was the one to kill Myrtle.
At the end of the book, when Nick ran into Tom, he realized that they see their actions as justified and not out of the ordinary. Tom thought he was doing the right thing by telling Mr. Wilson about Gatsby, and Mr. Wilson thought he was making things right by shooting Gatsby. Nick then felt as if Tom were a child or someone who needed to be taken care of by someone else. Which kind of pieces together perfectly with one's or other's views on someone's identity, and what some people see as right and others see as wrong.
At the end of the book, when Nick ran into Tom, he realized that they see their actions as justified and not out of the ordinary. Tom thought he was doing the right thing by telling Mr. Wilson about Gatsby, and Mr. Wilson thought he was making things right by shooting Gatsby. Nick then felt as if Tom were a child or someone who needed to be taken care of by someone else. Which kind of pieces together perfectly with one's or other's views on someone's identity, and what some people see as right and others see as wrong.