"No door remains forever locked against the man of indomitable will and courage.What we most lack is the power to continue:continuity and perseverance---the never quit spirit allied to intelligence is the secret key to success:not great natural endowments." Percy Wells Cerutty.
The biggest excuse a distance runner can give to explain his lack of success is to say, 'I just don't have the talent.' The above quote applies to all facets of our life,not just running.
Also,the path to success more often than not takes years.How many of us truly want to put the time in? But as I always say,in distance running,the joy is in the journey.