Weak can't help broken.
People that are weak have enough issues to deal with on their own. Often they try to help, but their effectiveness is limited because they are clearing their boat of the incoming water.
Strong people can help the broken. They can offer a hand up for the weak. They have the resources necessary to change a situation. They have experiences, financial means, and maturity acquired from a life built on a strong support system.
Your cup needs to be full to allow you to help others. Fix yourself first so that you can be more effective in helping others later. A solid foundation creates a better life for you and others in need.