I don't have time to flesh this out, but I just had a thought that I'd like to explore later.
There are six basic paths to pleasure, for a human:
- enjoying a physical experience (e.g., sensory input)
- enjoying a shared experience with someone else (i.e.: laughing at a joke)
- enjoying a sense of accomplishment (for example, "I just jumped 12 feet, I rock!")
- enjoying a sense of recognition (for example, "Dude, you just jumped 12 feet, you rock!")
- enjoying a sense of connection (best example being love)
- enjoying a sense of purpose (be it participation in a project, a sense of nationality, or religious experience.)