I've read similar things before, and totally agree with them, but surely 'the ability to work hard and persevere' varies a lot from person to person according to genetics and environmental factors?
To persevere is not a static unchanging quantity in itself. Its something you build over time. You start with the bare minimum, and it gets stronger with every failure.
If you look Usain Bolt and think I could never undergo such a brutal training regime, you must know Usain Bolt couldn't either. It takes a lot of tiny little failures to build that kind of mental stamina.
