You can add a friend when you met, the place where you met, story about your friendship, photos of you and your friend. This feature allow you to remember your friend and your friendship and keep the friendship alive forever with the story about your friendship.
How to add first met with friend :
Step 1: Select your friend and go to his timeline.
Step 2: Now from your friends timeline hover over Friends and click See Friendship.
Step 4: If you can't find the first met on the page just click on Recent and select First Met from top on the right side and follow Step 3.