How does the brain decide "what" thought to attach to a feeling?

The thought seems to be the mind’s attempt to interpret the body sensation. “Oh, there are tears running down my cheeks. I must be sad …”

When thoughts aren’t reflections of sensations (e.g. a thought about you’ve felt in your body, seen, heard, or imagined feeling, seeing, or hearing), they are reflections on other thoughts. We often have long chains of thoughts about thoughts about thoughts about thoughts… An example might be “… and the reason I’m sad is …”

We don’t yet have an answer from neuroscience. The best I can do is give you an anecdotal answer based on my years of meditative introspection. (I meditate for two hours every day.) For what it’s worth, I’ve heard many other longterm meditators give similar answers.

Why cant I sleep on my side after getting my covid vaccine? I just got the shot and I’ve been overstimulated from not being able to sleep, my arm is very sore and it hurts so much to move and I just want to sleep but it hurts if I lay on either side

A feeling (an emotion) is a body sensation swiftly followed by a thought. So swiftly that, without practice, they seem to come at the same time. In fact, without practice, it’s hard to see that’s what they are. We just call them “sadness,” “joy,” “anger,” and so on.

I’m really confused as to why “what” is in quotes, so it’s possible I misunderstand the question.