Sour, Bitter

I'm watching the final round of The Sopranos. The series became more and more sour as it went on, which isn't a bad thing. But I'm surprised the public loves such an unpleasant work. Maybe I'm not as out of step as I thought.

A side point. People keep misusing words, but everyone seems to understand the difference between "sour" and "bitter." I just checked Mac's Oxford American Dictionaries and they back me up (or it backs me up). Sourness does not necessarily involve self-pity; bitterness does. The definitions:

sour -- feeling or expressing resentment, disappointment, or anger

bitter -- angry, hurt, or resentful because of one's bad experiences or a sense of unjust treatment

Offhand, I can't recall seeing someone described as bitter without the implication of self-pity; nor have I seen anyone described as sour when his/her resentment over personal mistreatment was being discussed. "Soured on," yes, but that's different. People understand right off when to use one word and not the other. Which strikes me as remarkable when you think of all the traps people fall into with word use.