I learned this mantra while watching "Blended" with Adam Sandler and Drew Barrymore. It is absolutely one of the most accurate ways to describe parenting. We are all well aware that at an early age it does not take much to entertain your child or make them happy - food, a cardboard box to play with and they are happy for hours. While this stage does not last all that long in the grand scheme, you are there for the duration. A child should know that their parents will always be there whether it's an art class, a swim lesson, a basketball game, or just playing in the house on a rainy day. Children should not have any significant events or memories that do not include their parents in some way.
At the time of the milestone event or mundane activity, children may not recognize the importance of you being there. But they will. And over time they will go through phases when they want you around and when they do not want you around. You never want to be in a situation where your children want you around but you are nowhere to be found. They will remember that. If it becomes a pattern it will change the dynamic of your relationship and they will lose confidence that you are always there for them.
We would rather be the most boring, responsible, dependable parents in the world than being an absentee parent.