We crave instant success these days. If you are a really good sprinter and long jumper, you don't want to spend two or three years on a whole new set of events. You're used to doing well and it's difficult to give that up.

This quote is referring to how people today want quick and immediate success, rather than having to take their time to develop a new skill or talent. For example, if someone is especially talented in sprinting and long jumping, they don’t want to take two or three years to develop a whole new set of skills in different events. They are used to doing well and it can be hard to let go of that and start something new from scratch.