Even though the person has a significant other beside them everytime it can't always nourish that person who is going through hell.
Love erases pain and in most of the cases it's always the case, but, love can also make a person go through hell. Love isn't only based on two people.
And if love conquers all there wouldn't be fights among communities... a person who learns to love another person should know how it feels like to loose people you really care about. If that was the case there wouldn't be any conflicts among us.
^_^ I'm not being mean but Love is a strange emotion [or power] that tells us to move on, and it doesn't always dominate pain and sadness. For some people - a person might love his or her family too much, then why do some of them suicide?
Love is a smple thing yet it's derived into different feelings.