Experiencing Fear and Opportunity

Someone told me today they were afraid of dying. A recent sickness taught them of their own mortality. As children, we believe that we and all those we love will live on earth forever. It isn’t until we experience potential loss that we realize our time here is finite. Does this realization change us for the better? Do we, as humans, take this as the opportunity to experience more in life or does it create barriers with those we love for fear of losing them?