This should be a story that any MMO player is intimately acquainted with. You've just picked up an awesome new MMO and have been flying through the levels. It's gripping you and you really want to share it with your friends. Then you realize the fatal problem that occurs with most MMOs -- you're too high level and you don't want to wait for your friends to catch up.
With Final Fantasy XI, this was the brutal nature of the game. Being one or two levels away from your party resulted in decreased exp for everyone involved. Being three levels or more meant the party just didn't work at all and experience was ruined for everyone. It was unbearably hard to get parties, because everyone had to be within 2 levels of one another. With the recent advent of level sync, however, those days are long gone.