A promise to yourself still counts when nobody else knows you made it.

It is easy to treat private commitments as less binding because there is no one to disappoint. But the cost of breaking them is not social, it is internal, and it is paid in how seriously you take your own word next time. Each quietly abandoned promise makes the next one slightly less credible to the only person listening. Eventually your intentions stop convincing you.

Make fewer private promises and keep the ones you make. If something is doubtful, do not promise it, and if you have promised it, treat it with the seriousness you would give a commitment to someone else. Your reliability to yourself is the base that everything else stands on.