Strangers become friends; friends become strangers. That’s life. Sometimes, it is them; sometimes, it is us. What reveals the reason of friends becoming strangers can come in different ways: either you ask them or you make an in-depth self-examination where you went wrong. If answers still don’t come, then maybe, just maybe, you never shared any form of friendship with those people—at all. Just move on. Sometimes, people are better off alone. Enjoy solitude.