This is a game of dopamine hits.

When you complete the work you said you would, your brain releases dopamine.

Dopamine is your reward.

When you tell others your plans before even acting on them, this happens:

"Aecus told his friend Twesh that he's going to start running every morning.

Twesh, being a supportive friend, says it's the best thing Aecus can do. He praises Aecus for making this decision.

Aecus, who hasn’t even started running, gets praised. He received the reward. He got the dopamine he needed before even doing the task."

That's why you should keep your plans secret.

Keep it to yourself.

Earn that dopamine hit.