Every situation is different. I don't its common experience for anyone. So both are right

It depends on the circumstances. Take my second marriage. It was the happiest 5 years of my life. Unfortunately, we were married for 20.

I'm probably in the super minority, and don't wanna be 'that guy', but I don't really don't believe in marriage. I see it as an ancient way to denote property. Not that I'm against committed relationships.

Possibly...until the married one becomes widowed. Then the unmarried one remains in contentment.

I was more motivated to go out with friends when I was single. I also made more of an effort to get out and meet new people. I was happy doing those things, but I am happy being married too. There are pluses to both lifestyles.