In her book Mindset, Carol Dweck tells the story of Nadja Salerno-Sonnenberg (on the left in the video above).  She is a gifted violinist.  In her childhood she was considered a prodigy.  However, in her teen years she resisted instruction and nearly threw it all away.

Everything I was going through boiled down to fear.  Fear of trying and failing…if you go to an audition and don’t really try, if you’re not really prepared, if you didn’t work as hard as you could have and you don’t win, you have an excuse…Nothing is harder than saying, ‘I have it my all and it wasn’t good enough.’

At this point in her book, Dr. Dweck is refuting the idea that geniuses do not need to practice.  Our culture reinforces the view that the truly great do not need to work hard.  Their talents are so vast that everything they accomplish comes from talent they were born with.

This view is so paralyzing that it causes the person with a fixed mindset to give up trying because trying and failing would mean you might not actually be able to achieve what you want.  It also robbed Salerno-Sonnenberg of her motivation because actually practicing would rob her of excuses.  When faced with an ultimatum from her teacher at Julliard she decided to resume her training.

Below is a 2 minute clip of her talking about her approach to practicing years later.
(Note: YouTube has prevented this clip from being embedded so you have to watch it on their site.)

The bottom line is, you never know how good you can be if you don’t put out the effort.  It is true that you might fail to match expectations, let alone be a genius.  Remember where those expectations came from.  All a person can do is keep trying and learning.  This is the essence of the growth mindset.