A secret becomes less private each time its keeper tests how impressive it sounds near disclosure.

Holding something confidential is not only a matter of never saying it. Long before the words come out, there is the pleasure of almost saying them: the hint, the raised eyebrow, the remark that you know something about that. Each of those is a small withdrawal from the same account, and they narrow the field of possible answers until the secret is effectively public. The keeper usually feels they have said nothing at all.

Watch for the moment you want to signal that you are in possession of something. That is the point to notice, not the telling itself, and it passes if you let it.