I don't get it

I hate to see people that I care for in pain, especially at the hands of someone who supposedly loves them.  It makes me want to defend them, protect them, take up their battle and make it all better.  But the truth is, there is little I can actually do.  I guess realizing this limitation is a helpful, positive thing, but it doesn't make me feel any better about the situations I see going on around me.  What good is it to have gone through things when it's not useful?