You need to make a new effort in your 20’s to find new friends. After school, people tend to go their own way and form new friendships based on work and then eventually based on their kids’ social lives. Where you move also plays a big part. Every time you go into a new life phase, you tend to shed all of your acquaintances, hold onto 1-2 real friends, and make new acquaintances and 1-2 real friends - rinse and repeat.