Loneliness for many people is a time when they feel depressed, and it can age their body and mind as they wonder if they will ever find a long time relationship to suit them. They might fall into the belief they will never be good enough to find the right person, or they could be experiencing profound grief due to a lack of suitable partners available in their area. The reasons behind their depression matter little unless they are able to solve them, and it can lead them to an early grave if they continue to do the same things. Longevity with a partner depends upon finding the right person, but it can make the life of both people sweeter when they find each other.
Mutual support is one of the reasons many people find life with a permanent partner better, but love and emotional attachment is part of the package for most of them. They see a relationship as a way to make the life of their partner better, but the feeling should be mutual between them. Each person receives a dose of happiness when they help the other person through the trials of life, and they also feel supported when things go wrong.
Sharing the happy times is often what people talk about, but those who are lucky enough to find the right person know that sharing the sorrows of life is what binds them closer. This support system with another person will help them weather the ills of life better, so it tends to give them an opportunity for a longer life.
Few people really want to go through life completely alone, but some of them will never find just the right person. They might be willing to settle for someone close, or they could spend their many years in the search for their perfect mate.