Every year they decide who to give the gold ball. What you need to do to win the gold ball is be one or the best player in your team, make other coaches of other teams invited you many times to many team's so you bacame more popular, Be the best players in the world cup, score many goals, don't get too much yellow card or red card and many other things so many of the football player have many chances to get these kind of opportunities.
Messi had won many gold balls since 2009 to 2012 so that means he had won 4 times 4 years. Messi won this gold balls because of his best effort, talental,his energy and being the best futbol player in the games they have or in the world cups he had played. Even if he score goals he continues winning points.
The difficulties for Messi during games were that he had many rivals and every one attacked him because he always have the ball. There was a time were he start being rud and every one was not happy about his actitude because he was being rud and always mad when he was playing games. There was a year when he won the gold ball but he didn't want it because they say he didn't deserved it.
One of the most important difficulty Messi has since very young is that he went to the doctor when he was nine years old and the doctor told him he had a growth problem and that was not going to grow much like a normal person so that means he could only grow a few centimiters. But the doctor told him he could have a prosses of injections like 2 pear month more less and that shots will help him grow a few centimiters more so thats why he is not to tall right now.
This kind of things are super important for athlete. But this kind of things are not just trying winning losing giving up or those things, this things you have to just keep trying winning or losing just do your best effort thats how we demostrate the world we can do everything said Messi.
In the past few years Cristiano Ronaldo has been beating him but it seem that this year he will start beating him again. We still dont know who will win the gold ball.