Nothing great lasts for more than about 18 months

A few years ago, I noticed an effect in discussion and support groups that met regularly. At that time (before kids, Facebook, Twitter, etc..) I was a lonely guy, and used support groups as my social activity. "The 18 month effect" goes sort of like this: You join a group. You make friends, and look forward to showing up and seeing them. You think that this great feeling will go on forever, and you will all walk linked arms into the sunset. After a few months....a few stop showing up. Then new members show up and leave. Then the charasmatic leader (that calls everybody once a week to remind them to come): gets sick, or looses interest. On and on it goes. Then one day, you get bored, and stop showing up. This cycle seems to take about 18 months to run out. If human group activities go on much longer, they either have to change, renew, or die. Those that do not see the need for change, usually don't die. They just stay where they are year after year, trying to keep the same old thing going, while others move on. That job that you just got that will solve all your problems, will change or disappear in about 18 months, just as you become the master of your craft. One day when you show up for work, you will have a letdown feeling. Boredom and conflict will set in. That's the signal that you will have to grow or move on. What will it be for you?