I'm motivated by the fact that I love my curly hair! I no longer feel the NEED to straighten my hair. If I ever do (which is maybe three times a year), it's because I want to.
My best friend was the catalyst in getting me to grow out my damaged hair and embrace my natural hair...he still tells me all the time about how much he loves my hair. I think that's also another big motivation: being surrounded by positive people who will help you love your hair!