A successful life is down to how adept you are at attracting personal and professional opportunities into your life, and the lives of everyone else you know. Meeting new people face-to-face is the single best way of doing that. It applies equally for purely social events as well as work related parties, drinks receptions etc.
Suddenly on your own again, with the disappearance of all the family chores, it can be a frightening prospect. All of a sudden you have to accept that your child rearing days are over. You have to adapt to life solely with your partner or on your own, and you have to think about what you are going to do with all that spare time, previously taken up with family activities.