In high school, friendships tend to be complicated. Or, if not complicated, fleeting. You form a tight bond with someone, and then, just as quickly, something tears it apart or life takes you down different paths and suddenly, the girl who was your BFF is your mortal enemy, or, less dramatic, someone you half-wave to from across the cafeteria.

In adult friendships, as much as things change,  things stay the same. You form friendships. Sometimes you stay tight. More often than not, they don't s...