What's the hardest part about being a parent?

As a parent, we want to shelter and protect our children but in order to grow up, children have to learn how to overcome obstacles on their own. Also, the thought that she may one day be bullied or hurt by someone because we can't always be there to watch over her hurts. I think the hardest part about being a parent is to ensure that children grow up with proper values and upbringing. You can teach a child so much, but children also get influenced by their surroundings especially in their growing up years.