“There are no secrets better kept than the secrets that everybody guesses.”

Simplified Meaning:

Sometimes, things that are supposed to be hidden are actually known by many people, but no one talks about them openly. It's like when everyone in a small town knows about a couple that is dating secretly, but no one brings it up because they don’t want to spread rumors or cause trouble. Even if people guess what’s happening, they act like they don't know. This makes the secret seem well-kept, even though it's not really hidden. One can see this in workplaces where everyone knows a certain employee is going to get a promotion, but they all pretend they don't, so the surprise is maintained when the announcement is officially made. By understanding this, we learn that sometimes the best-kept secrets are those that aren't really hidden, but everyone agrees to keep quiet about for harmony or respect.