I read somewhere that she believed "Rumble Fish" to be her most prolific work, it was the hardest to write and the most profound. I don't feel that way. I read "That was Then, This is Now" and thought it had a maturity that the others did not have. I enjoyed the voice and prose of "The Outsiders" and the feelings it conveyed, but "That was Then.." is the best in my opinion. It speaks to teens to do the right thing, to change direction and go the limit to set things right. The end is bad, the main character turns his best friend in for drugs, that's why most people hate the ending...I thought it closed the story well. We see that Mark is bad, he's the boy who will not grow up and will not think about the future. Bryon is the mature boy, he takes responsibility and control, he takes care of his mother and his life in the end. You have the feeling that he is mature from the beginning, he recalls how he grew into the man he is. It's a bit more complicated than her other works, but well worth the read.