Malcolm Gladwell introduced the concept of the “10,000-hour rule” in his 2008 book, Outliers. As Wikipedia describes it, “…the key to success in any field is, to a large extent, a matter of practicing a specific task for a total of around 10,000 hours.”*
Gladwell does not specifically say that 10,000 hours of practice or apprenticeship will make you an expert. Like most things on the internet, it has been altered in the transmission; dumbed down for the simplistic misquotes we love to pair with pictures of kittens or puppies on Facebook.
Rather what he said was that it will make you damned good. Way above the rest. A phenom, as Eric Dekkers said:
…he’s talking about those surprising success stories who stand head and shoulders above the elite performers in their industry. That one guy who is way better than the 31 other “best quarterbacks in the country.” That one woman who fearsomely dominates all other female tennis players in the world.
Still, the concept and the generalization behind it have not gone unchallenged. As science writer David Bradley wrote for the BBC,
Scientifically speaking, 10,000 hours is not a precise figure but shorthand for “lots and lots of dedicated practice”. Even 10,000 hours of dedicated practice may not be enough to give you the skills of a virtuoso. But whether you dream of playing at the concert hall, wielding the guitar, or taking part on the running track, 10,000 hours is a good starting point. Double that and you may even be winning international competitions.
Bradley also notes that 10,000 is a lot of time doing repetitive practice:
To notch up 10,000 hours would require about 90 minutes of practice every day for 20 years. This might explain why the typical child learning the piano will never make it to concert level. Three hours a day gets you to that stage within a decade, so start at the age of ten and you’re done before you’re out of your teens.
Imagine you’re a 10-year old starting violin lessons. Your parents make you practice an hour every school day, but give you weekends and holidays off. You might be able to get in 195 days or practice a year. At that rate, it would take more than 51 years to reach Gladwell’s 10,000-hour “expert” level.