To me it means you have had someone special in your life but you've lost them in some way or another. Whether it be death or them walking away from you. No matter who it is they were very special to you and could lift you up, but when you need lifted up because of them leaving you no longer have that person to lean on or help you rise above it. Then you find you need to be strong on your own by ending the current problem your facing and mending your pain and broken heart.