Privacy allows experiences to belong to you before they belong to the story about you.

Once you tell people something, it starts becoming a story, and the story develops its own requirements. It gets shortened, given a moral, and repeated back to you in a shape you did not choose. Keeping an experience to yourself for a while means you get to have the thing itself before it becomes the account of the thing. Those are not the same possession.

After something significant, give yourself a period where you do not summarize it for anyone. Write it down privately if you need to hold it somewhere. Tell it later, when you know what it was.