A man went to a party and drank some of the punch. Late for another appointment, he then left early. Everyone else at the party who drank the punch subsequently died of poisoning.
Why did the man not die?
I believe this is another of those yes / no type laterla thinking puzzles, and having seen it before, know the "target" answer, but I won't spoil it. I'm curious to see how many different and (by the question) legitimate answers we can come up with.
Having just watched "The Princess Bride", I'll suggest that he had built up an immunity to the poison used. (though I'm aware thats not the answer Anoop is looking for...)