Like it or not, want it or not, the best predictor of future behaviour is past behaviour. When someone has treated you a certain way the last fifty times (positive or negative), there's a fair chance, that's what you'll get next interaction. And despite the historical evidence - the poor treatment we've received previously (for example) - some of us curiously (and illogically) will expect that person to magically 'be different' next time. It's one thing believe that someone can change for the better (and some will, of course), it's another thing to analyse the data from previous experiences through a lens of logic and reason and to know that statistically, we're probably in for more of the same. It’s nice to be nice, but it’s not nice to be a doormat.