I believe that our lives are preordained and our destinies are fixed. But here is necessary to mark that our fates are predetermined only in a sense of their meaning (content). As for the shapes or forms, we can choose them pretty freely. For example, let us imagine that a great painter was born. But in his life he never painted. In fact he died as an unknown and ordinary person and nobody found out that he was a great (potential) painter.
Since his birth he had a number of possibilities of becoming one, but he chose none. A choice is a relative notion and ultimately depends not so much on the person but the circumstances, time and etc. Never the less the great artist was born and no matter what his life was like he died being a great potential artist. His mistake was that he failed to recognise his artistic potential and therefore didn’t choose pursue it (or pursuing wrong forms). His destiny was fixed in terms of meaning, but he had the freedom to follow a different path