happiness being left in the past

The other day I was sitting with the sun shining on my face and listening to a song called "you could be happy" by Snow patrol.
What came to my mind at the time is that I might not allow myself to embrace happiness as much as I could. In previous post I was talking about expectations and how they are usually built on sand but not carved in stone and based on sound reasons. And that is why they break down easily.
That for me, is the story of my search for happiness.. I build my hopes and happiness on the sand I have around me, hoping for the stable future.

But one's mind is hard to change when it has decided something. I believe that's also why my reasons are not solid. Because I'm stuck in the past, not allowing my head and heart to move on.
Dont get me wrong.. whenever I think more about this, I belive I allow myself to depart more and more from the past but it's a long and tiresome process.

Maybe this is all about not allowing me to embrace who I am and what I have to offer to new people in my life?
Or scared that the happiness and love once had will never return, and therefore I hold on?
But it wont come back, not the same love and happiness. Potentially, if I allow it, it will be even better.
But I feel I'm not allowing this to happen - at least not as fast as it could be.
I wonder!