What does our real happiness rely on?

If we have everything to make us happy, and obviously this means different things to different people. In my first blog i illustrated some things that might make us happy,and give one a sense of fulfilment and purpose. I also illustrated some reasons why we might feel unhappy and unfulfilled, even perhaps lonely and depressed. I think the point is that all the people,places and things that our happiness relies upon can at any point be taken away, or radically altered. It happens ever day, when tragedy strikes in the form of a bereavement, or being told that someone you love dearly has a life threatening illness, perhaps it is you who have this illness. Your partner wants to leave, or you want to end your marriage, or relationship. Maybe you have fallen in love with someone who fulfils a part of you that you thought had die. But you have a couple of children, and weigh up all the pros and cons of this complex situation. Life it seems is full of decisions and choices, nothing it seems is black and white, if it was then how much easier every choice we make would be. If only true happiness was to be found in an attitude of mind, rather than us being a hostage to whatever fate and circumstance seems to throw our way. This seems to be the conundrum of life I feel, how do we know when we are right?