If I correctly read what you're saying, you're basically asserting that you can be sad because your belief structure has changed. That implies to have meta-beliefs, which are extremely dangerous from a rationality point of view.
As a rationalist, you should keep your identity very small and do not presuppose anything about the general structure of how your beliefs should be like, because you will be almost certainly wrong (and disappointed).
Consider this extreme example.
On the other hand, I don't understand the Paul quote: we're exactly saying that you shouldn't be judgemental (about reality, that is). Obviously we're talking about ideals to aspire, as with everything in this forum and self-improvement.
No, it does not imply that you have "meta-beliefs", although everyone does. It implies that your beliefs affect the world, as for example by making you say things. If your beliefs affect the world, changing your beliefs will both change the part of the world which is your beliefs, and also other parts of the world. All of that has the possibility of making you sad.
This is all perfectly obvious, and I should not have to bring up examples from real life.
If it's worth saying, but not worth its own post, then it goes here.
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