If a friend disapproves of your relationship, getting some solid perspective from your friend can ”allow you to have the kind of discussions that help you preserve your friendship," says Dr. Miriam Kirmayer.

Having a friendship with someone who is older allows for a “window into a different life experience or state,” says Dr. Miriam Kirmayer.

So what can account for the big friendship shift that seems to occur once you hit your third or fourth decade? According to Dr. Miriam Kirmayer, the answer is simple: life.