Holden decides not to run away and return home. He starts to reflect on everything that happened to him. He thinks twice on his decision. This is an AHA moment since this change a lot of things he reflects and now is going to be smarter since he misses the people that were in his life before.
About all I know is, I sort of miss everybody I told about. Even old Stradlater and Ackley, for instance. I think I even miss that goddam Maurice. It's funny. Don't ever tell anybody anything. If you do, you start missing everybody.
The resolution is he undergoes the acceptance and understanding of growing up/maturing. He is seeing his little sister innocence and seeing a childhood. His was ruined since the loss of his brother and he misses the sense of innocence that he once has and now needs to learn how to grow up and mature.
"damn near bawling, I felt so damn happy, if you want to know the truth. I don't know why. It was just that she looked so damn nice,"