In order to be a world-class expert in anything, be it audiology, drama, music, art, gymnastics, whatever, one needs to have a minimum of 10,000 hours of practice. Unfortunately, it doesn’t mean that if you put in 10,000 hours that you will become an expert, but there aren’t any cases where someone has achieved world-class mastery without it! So the time spent at the activity is indeed the most important and influential factor.
