Sometimes the safest secret is the plan nobody knew existed.

A plan that nobody knows about cannot be argued with, undermined, or gently talked out of you by well-meaning people. It also does not have to survive anyone’s early scepticism during the fragile stage when you are not yet sure of it yourself. Privacy is not secrecy for its own sake; it is protection during the period when the idea has no defences. It can go public once it can stand.

Keep the next thing to yourself until it exists in some real form. Tell one person if you need accountability, chosen carefully. Announcing early tends to spend the motivation you needed for the work.