Mormon 1
It is interesting to note that there were no wars (contention and pride, but no wars) among the Nephites and Lamanites after Christ came until the time of Mormon. also interesting is the fact that the 3 remaining disciples of Jesus were not taken from the people until they began to have wars.
I think that when he was young Mormon wished that he could have been taken with them. perhaps later he realized that his mission was equally important to the work of the Lord.