I've found that children feel the best about themselves when they set out to accomplish something (whatever that may be) and follow it through until it's done.
It's something that carries over into adulthood, and helps shape a person's character.
I agree with you which is why we as teachers set goals with the kids. My big one is to have all of them read on grade level by the end of the school year. The great majority make it and those who don't are close. The last two years everyone has.