I don't see what else it could mean. Why would P!=NP change his life dramatically? Maybe you're thinking of P=NP?
P≠NP is exactly the ‘expected’ answer! But proving that
expected answer has been the central goal of the field
for 40 years—not so much (in my opinion) because the
answer itself is in serious doubt, as because of how much
will need to be learned about computation on the way to
the proof. If P≠NP is proved, then to whatever extent
theoretical computer science continues to exist at all,
it will have a very different character.Oh well, maybe this guy's life will change if P!=NP is proven, but the rest of us will carry on normally.
1) It would solve one of the most important problems in computer science and mathematics 2) Understanding of the proof and the methods it uses could very likely lead to solving other problems in computational complexity. 3) Furthermore, the proof would shed light on why certain problems are hard. Such an understanding could lead to better heuristics to solve those problems.
BTW, why can't I respond to sidww2's comment? There's no reply button.