Do what you love. It will feel like you ..

And ... It will be authentic.

“Intellectual passion drives out sensuality"Leonardo da Vinci

In any sport, profession, or competition, the difference between the top 5% and the rest of the crowd is passion.  The top 5% are typically exponentially better than the next in line and not just a little bit better.  This is because they are passionate about what there are doing and therefore achieve greatness.  

Hard work only does not produce success. It does not sustain success.  It is passion that drives success. Love for one's activity is infinitely more important to creating success than hard work. Yet for some obscure reason, we all : parents, teachers, and managers insist on emphasizing the importance of hard work - Do we really need hard-workers?

You can achieve modest results without being passionate, but it's unlikely that you will be able to compete with more passionate people.  They will work harder, longer, and pay more attention to detail than a non-passionate person.  The result will be a glaring difference between you and them.  So, to achieve great things you need to be passionate.

A excellent book on this topic is Ken Robinson’s “The Element: How Finding Your Passion Changes Everything”.  Element is where passion for doing something meets talent or aptitude  of doing something.