Why is it that it is so hard for me to let things flow?

Fear I suppose... If it's true what they say that 'We fear the things that already happened' then it must be fear of visiting a certain feeling or state of mind that I have been in before. Shouldn't I get used to a feeling with time? Wouldn't it make more sense to be less afraid of it? But somehow being so familiar to a feeling that I 'dislike' makes me try an avoid that particular feeling.  I guess the next logical question would be to ask myself: Why do I dislike that feeling? Maybe because someone told me that being sad was bad and I believed it. Maybe because people I trusted made mistakes and I saw that as betrayal.  The interesting thing is, no matter how much I try to avoid something... nothing is avoidable. Everything happens how it must no matter how much we try to change it. Love happens, sad happens, mistakes happen, happy happens, fear happens... So if I skip the 'avoiding the feeling' and let things flow how they will, even if I am afraid. Maybe my path will become more clear. With less noise...