They says that everyone has secrets, and it's true. We all have things in our lives that we keep to ourselves or are selective about who we tell. Sometimes we do this to protect ourselves, sometimes to protect others. This is perfectly understandable.
Certain things aren't the business of acquaintances or strangers, even to some extent, friends. Things like gender identity, sexual orientation can get people hurt or killed. A loved one learning we're an abuse survivor can be cause them a lot of pain, and explaining it can drag us back to a place we don't want to remember.
But at the same time, keeping secrets from loved ones can be hard and when the come out, the fact that it was a secret can hurt just as much.
It's important to think carefully about who we share things with and who we don't. None of us can live with no one to share things with, wearing a mask with everyone in our lives. But it's just as important to remember that when people keep things from us, that their reasoning may not be deceitful or malicious.