Why are people afraid of being alone?

I don't understand this for the life of me. I am in my late 30s and I cringe when I hear people say they just got out of a relationship with XYZ problems or they are in a relationship now with XYZ problems. Then the very next thing they say is that they are going to find someone who blah blah blah. Why are people afraid to take time to get to know themselves and have time to regroup and breathe! Please understand I am not judging at all I just have a hard time understanding and would appreciate any insight on this if you are this type of person. And for the record I am married but I strongly believe that when a relationship ends you need not jump right into another one. When I was single and if I ever happen to be single again I would not be looking for my next relationship right away. Do you agree or disagree that every person (man or woman) should have some time in their life to focus on and learn themselves without the influence of another energy in their daily lives?