Everyone knows the saying 'think about number one' meaning that you are the most important thing in your own mind, your own world and that you always put yourself above everyone else. I do agree with this to a certain extent but the time this changes, is when you become a parent.
You can then not just think about yourself as 'number one' but now your children are the most important things in your life. They should always be put before anyone/anything else, even before yourself.
The natural state of motherhood is unselfishness.
When you become a mother, you are no longer the centre of your own universe.
You relinquish that position to your children.