Basically, if you were offered an opportunity to travel to travel on the first manned mission to Mars with, say, 10 strangers and start a human colony, would you take it? You would have to leave behind your family, friends, pets, and life as you know it. On the other hand, you would be one of the first people to go to Mars!
Personally, I'd definitely go, as a huge space nerd, and the fact that I would finally be able to do something useful and make a difference. To be brutally honest, nobody would really miss me, and most people would be happier if I was 225 million km away from them.