Dengue Fever questions

Are some people less likely to get dengue even if they've been bitten by the mosquito that carries it?

Is it possible to have a mild case and not realize it? Is there even such a thing as a mild case?

I ask because I've lived in Thailand many years and been bitten by mosquitoes just about everywhere I've gone. I'm just wondering whether is it just dumb luck that has prevented me from contracting dengue fever so far, or are there any factors that might make some people less likely to come down with it than others?

When you think of it, there are lots of people living in areas where the disease is endemic who do not contract it, even though they must be getting bitten by the mosquito carriers as much as anybody else.