I love this line: Hard work beats talent when talent doesn’t work hard.

Yes, obsession and passion can be crucial to one's success.

And I wouldn't fret too much over any preceived notions of intelligence. While intelligence in the logical sense is important, there are other forms of intelligence that determine one's success, and many high-IQ people flounder in other areas of life because they don't, or cant, apply their IQ in those areas.