i see it alot in my surroundings.
lot of my friends are married or getting married.
what i saw was that your sosial life changes. you "roll" into it before you know it.
before you go to partys and visite pubs, meet with a lot of people,talk ,drink etc with everybody.
the (biggest)amounth of people you get to know is at your most active social time, and that mostely is when your young.
when you grow older people break up,
when you get married you will be more isolating your self from the other. settle down , like i call it.
And then a child comes. your sosial life is now reduces to a few friends,parents, familie and maybe the neighbours.
so when married you will loose a lot of your "territory"
there are always exeptions ofcours!