One day I realised of one thing. We humans spend huge amount of our time at work. Since we leave school till we retire we work on average 8 hours per day, excluding weekends. A day has 24 hours, so that's almost one third. If we take in account that we sleep for about another 8 hours we can say that almost half of our awake lifetime we will spend it at work! That's a lot of time to waste it at something that you don't like.
From that day it's been clear to me. I had to work on something that I would enjoy and at the same time I would have to enjoy my work. That's why I am a software developer and that's why I love it.