The boys are only 22 months apart and at a time when L could have really spiraled into his own world unchallenged, constant interruption from a younger sibling forced L to confront so many of the issues and interactions (e.g. sharing, compromising, perspective-taking, and so on) he would have preferred to avoid. Now don't get me wrong. L is still challenged by all of those behaviors and concepts, it's just that with Z around he gets to practice coming to terms with them on a daily basis.
|First Meeting :)|
|"The sun is in my eyes!" Holding on for dear life to little bro.|