Remember when Michael Jordan thought he could play baseball?

What is it with the elite athletes thinking they can play anything?  Usain Bolt says he wants to kick a ball when he gets done running. 

“I always watch those guys and I think I could be a professional footballer. I’ll try that — maybe I could get into a good side or even an average side.”

I guess if I look at the bright side, perhaps the World Cup is a little more interesting if he plays.  What am I missing about soccer?