As with all things in life it really depends on how you frame it.
As a young man I encountered many people who were unkind, told me that my goals were impossible and mocked me for my ambition. Now that I have succeeded at those aims and continued to grow as a human being it is a great feeling to encounter those people in life and see that they haven't been as successful as I have. I can't help but think that I perhaps wouldn't of made it through all those hard years struggling had more people believed in me, the desire to prove them wrong and get my revenge remains one of my greatest sources of motivation.