There's a difference between interest and commitment. When you’re interested in doing something, you do it only when circumstances permit. When you’re committed to something, you accept no excuses, only results - Art Turock

The only way to make a commitment long lasting is to choose to do what you are naturally passionate about. That’s way you will most likely keep going, keep trying when things get hard, when results have not come yet, when you don’t feel motivated. Even when you are stuck, you won’t just give up or give in easily to the naysayers. 

The thing is that going for your dreams is never easy, and it is very important that you choose something we love so that it makes it easier to endure.