One of the mistakes people make, is making a promise without thinking twice. Some people make promise when they are over joyous and its has led to them getting into serious trouble. Some people make promises for different reasons, just to get rid of that person at that particular moment,or to get something from someone,or probably because they are over joyous.
Before you promise that particular person heaven and earth, make sure you think twice, its better to keep quiet when you are filled with joy than to regret making a promise that you cant fulfil later.