This is very true. Some psychologists and clinicians think that depression and other neuroses come from entrenched and dysfunctional "habits of thought", or interactions between thought and behaviour. One particular theory along those lines that I believe in is "attributional style". It's the theory that depressive people tend to attribute successes to things that are external and temporary (e.g. "I passed that exam because it was a lax examiner that year") and failures to things that are internal and permanent (e.g. "I got dumped because I am worthless"). If that style of thinking becomes entrenched, you become more likely to be depressed.
This is *very* common: people who are unhappy thinking that they have no right to be unhappy, and this making them even less happy.
IMO, part of it comes from thinking that happiness level should be like a thermometer or something, which is based on your well-being, calibrated to a global scale. I don't quite know what happiness is, but whatever it is, it is not like that. And who gives a fuck if it *should* be like that. You have to deal with the actual mechanisms that compose you, not madeup ones.
There probably *are* some sort of judgement/rational processes involved, but what is very clear is that they can become broken. As I mentioned above, weird and dysfunctional ways of thinking become entrenched. And so the happiness level that your mechanism is supposed to produce gets nerfed.
If you think along these lines (which is how cognitive psychologists and a large school of treatment professionals think), then you can think of depression and other neurosis as a systemic dysfunction, not unlike a muscular imbalance or a tracking failure. Then you don't have to beat yourself up for feeling bad. You don't feel bad because you're entitled, you feel bad because you've slightly screwed the evaluating and judging mechanisms that underlie your normal mood and levels of happiness.
See above.
