He could see why she left, there were many reasons but they were different from Andie's. The C.J. in California wasn't the same C.J. as the one in New York and vice versa. In the end he decided there was no one C.J.; she was multifaceted, like a jewel, a diamond.
"I am finally seeing why I was the one worth leaving."
There was the young C.J. in Ohio and later at Berkley, the one who would debate with him and sleep with him. The C.J. in New York, who he loved, lived and sometimes worked with; that C.J. was so vital to his life, so essential. There was a second Californian C.J. she was older, wiser, and still as clumsy, sexy and sarcastic as before. Between those C.J.'s was the one who was his best friend, who he wrote to, long rambling letters and who would have been the best man at his wedding if she hadn't been a woman.
Then finally there was the 'Bartlet' C.J.; the C.J. of long campaign nights debating, arguing and often throwing things at Josh. There was the White House C.J. who evolved from her campaign self. This more mature C.J., the professional, still drank and debated with him but wouldn't sleep with him again for many years.
"You seem so out of context in this gaudy apartment complex."
In the end it was the C.J. he came home to, the C.J. he'd loved for most of his life; the one who gave him a second chance, the one who made him smile. Yes she left him, and he left her but they came back to one another, older, wiser and better than before.