Not all Fields medalists are made equal... :)

Really: It's just a side effect that he got the Fields medal.

I don't know him personally, but I know several (unrelated) people personally who worked with him, and based on their stories + information available on the internet I was equally impressed by him before this medal event...

That guy simply has an impeccable record of achievements from age two on (disregarding a lot of other prizes)

• age 2: Teaching himself arithmetics (from Sesame Streets)
• 8: Scoring 760 on SAT in Mathamatics
• 10: Winning bronze medal at International Mathematical Olympiad
• 13: Winning gold medal at International Mathematical Olympiad
• 17: Master in Mathematics
• 20: PhD
• 24: Full Professor at UCLA
• 31: Fields Medal
• 34(now) 140+ publications and 9 books in various different fields of mathematics, like: harmonic analysis, partial differential equations, geometric combinatorics, arithmetic combinatorics, analytic number theory, algebraic combinatorics and representation theory.