As a parent you want your children to succeed, to be responsible citizens and good people when they reach adulthood, and to be self reliant. Many parents make the common mistake of trying to do everything for their child in an attempt to protect them and make life easier. If you want your children to be successful human beings then it is necessary to teach them to do for themselves, and let them learn from their mistakes no matter how painful these may be. When you children know how to do for themselves then they will mature on an emotional level and will not need to rely on anyone else. As long as you do things for them your children will never feel the emotional high when they succeed at something for the first time after trying and failing in the past.
If you want to raise children who are successful as adults then you need to teach your children how to do things on their own. As long as you do things for your kids this fosters a dependence on you, and when you are no longer around your children will not know what to do or who to turn to. As a parent you need to raise children who become adults who are independent and motivated to succeed, and no success comes without a few failures. Teach your children how to do thing themselves, and then fight the urge to jump in and help if it looks like they will not succeed this time so that they learn from their failure and are more motivated to succeed on the next attempt.