Why can't I keep my plans a secret? I make many plans for my personal growth, and at the time of making a plan I decided to keep my plan secret. However, at the end of the day, I tend to share that with others. I can't understand why do I do this.

Check your level of self-confidence, perhaps you are seeing attention and appreciation prior to the completion of your desired target. The sixth sense in you is unknowingly forcing you to spill that look what am I doing. One thing for sure other than this that you are a very simple and kind human.