Sunnydale, and occasionally the world, revolve around Buffy Summers. Something that most people feel at times is a vivid, real experience for Buffy.
But Buffy hasn't had a center for a while and without that, everything started to spin out of control. Is it only a coincidence that everyone else starts to get their act together when Buffy does?
The main flaw that people accuse Buffy of seems to be selfishness. In a sense, I believe that they are correct, but it is a grounded and remarkably selfless selfishness.
What Buffy has is a tremendous sense of responsibility to her friends and to the world at large. She believes that to be a Slayer she has to be emotionally as well as physically strong.
What starts out as a good, the lesson that 'with great power comes great responsibility'(Spider-Man), is pulled out of shape until Buffy feels like she has to not only be Protector to the world but also never show the strain.
Buffy has had many 'turning points' this year. Although they seem repetitive at times, it is a truth that the world will keep forcing lessons on you until you learn from them.
Buffy hasn't yet learned that the greatest way to augment her strength might be to allow others to shoulder some of her emotional burdens.