I need heroes, not adventurers.

I was driving in the car the other day and I realized something about the way I like to run long campaigns.  A lot of my former players didn't last very long, and my playgroups have almost always been small.  I realized that it's not really player differences, it's playstyle differences.  When I run a big campaign, I like for it to be detailed and personal.  I try to make it seem like a real world with real people that they are interacting with.  And it's for that reason that I expect a higher level of character development.  I don't need backstory, but I need motivation.  I need realistic reactions to the characters around them.  I need characters who have hopes and fears, who learn and grow.  I want my players to want to do something that would make a lasting change in the world around them.  You don't play the fighter who quests for gold, you play the blacksmith's son who always dreamed to ride with the knights he helped his father equip.

I need heroes, not adventurers.