People's very first gut reaction to something (or someone) usually sets the pattern of thought about it firmly in their minds...either they are positive or negative about it. Then they spend the next five years doing what they can to reinforce and defend that first impression. As time goes by they must defend it ever the more fiercely because of all the past investment of effort and feeling they're already put into defending it. Kind of like the American military in Vietnam. Nobody wants to be seen as "a quitter" or as someone who didn't get in the last word on the matter. ;-)

That's what I usually see happening in the personal arguments that arise between people here too.