Just read a book called Bounce by Matthew Syed. Its central point is that excellence in sport or indeed any field of endeavour is not a question of inherent talent, but a question of practice, hard work, self belief, mental toughness, support and a little bit of luck.
It makes you think about what is possible rather than what most of us do when we stop (or don't even start) trying - that we can't get better at what we do because we lack talent. I see it every day in the classroom when kids start off saying that they are no good at maths and so set themselves on the path to underachievement. I saw it every day at Diageo when we gave up on a product, campaign or person before we had put any real effort or time into making it work. I include myself in that group as I have never worked that hard at anything.
The suggestion is 10,000 hours or 10 years. It's interesting that my finest career moment in marketing was working on Johnnie Walker from 1999 to 2004, 10 years after I started work. Watch out education, 10 years from now.
My half marathon time has dropped from 1 hour 45 in 2003 to 1 hr 26 this year. 19 minutes improvement, completely down to training. Now I'm thinking, how quick could I run?