Most sensory signals just provide raw information, but our pain and pleasure nerves trigger special classes of signal, prediction and reinforcement, and therefore motivation. And because of transitivity, our experiences can acquire abstract indirect dimensions layered on the direct physical signals.

(This is an analysis, not experimental truth.)

Pain nerves do at least three things:

1. Generate a normal sensory signal. "Your hand is hot."

2. Trigger a common pain sensory signal. "Your hand is too hot."

3. Trigger the adaptation of a pain prediction model, with a pain prediction signal. The prediction signal is a reinforcement signal that physically ensures: "You do not like your hand to be too hot."

That reinforcement happens in two ways:

4. Trigger negative reinforcement for any action predictive of pain (initiating or maintaining). "You are very motivated not to touch or hold that hot plate!"

5. And positive reinforcement for any action that is predictive of escaping pain (avoiding or reducing). "You are very motivated to wear kitchen mitts before picking up that plate! Or pull you hand away if you accidentally do!"

Which results in motivation:

6. We automatically choose actions that avoid pain. We automatically choose actions that extinguish pain. It would take counter-motivation action NOT do these things.

Pain prediction, and therefore reinforcement, are transitive:

7. Any state that predicts a state that predicts pain, becomes recursively predictive of pain. "You don't like your hand to be too hot -> holding things that are too hot -> holding hot plates."

8. Any action that is predictive of a state change that is predictive of a pain change, gets recursively reinforced (positively or negatively). "You are motivated to avoid touching hot things -> from touching hot plates -> to wear kitchen mitts."

And the dual of all those effects for pleasure.

The transitive/recursive learning helps us to avoid pain, and seek pleasure, at a very high indirect level. For instance, the pleasure of drinking wine or eating sushi, isn't just the physical pleasure of drinking and eating when we are thirsty or hungry, but our bodies prediction that those things will make us feel good over the next hour or so after consuming them.

Now add self-awareness.

When you consider things predictive of pleasure, you feel the the prediction signal, reinforcement, and motivated for that thing.

This is "wanting" and "liking".

When you are in a state producing the pleasure signal, you feel that signal, continued reinforcement and motivation to stay in that state. This is increased if the state is also associated with future predicted pleasure (i.e. sex feels good physically, but is also predictive of relationship stability, validation, etc.)

That makes the experience of "pleasure" far more complicated and meaningful than plain sensory signals.

When our body or mind turns off the pleasure, especially in a way we predicted it would, our motivation stops and we feel ready to move on.

That is "satisfaction".

I think "happiness" could largely be a state where we have high confidence of predictive high level pleasures going forward, or at least in the moment. I.e. peace, success, positive social situation, lack of worries, interesting challenges, etc.