Music.
The experience of making music. One morning you wake up and there's nothing. Later that night, it exists. You can play it back. You can sing along and dance and laugh and cry. Earlier it didn't exist and now it does. And it happened because you/we did it. That's the beauty of creation. The satisfaction that comes from, "this didn't exist and now it does and its because we said so", is greater than any drug.
I have had this experience with a lot of people this past year. It's been variety of things. Solo artists, bands, rock, pop, indie folk, bluegrass, soul/funk, roots, blues. All of it has been inspiring for the same reason with different genres bringing their "thing" to the studio. But all is the same, you make something from nothing.
As a recording engineer/producer you have a uniquely auspicious role. Essentially, you become an additional member of the band on a short term rental. You are a temp. Essential, but temporary. I always talk to bands and tell them I envy them for this reason: "When we are done with this, you get to go out and tour and play live. You are physically spreading the gospel of the work we did together. I get to see that through a different filter, watching on the periphery. You get to feel it personally from the fans. Hand in hand."
There is a reason why your name is in large print on the front of the record and why my name is in small print on the back. I have skin in the game. A lot. But only a fraction as much as you. What's your pay off? You get the process of creating but you also get the euphoria of the crowd. My payoff is in that creation. When I get home, pour myself a beer or a bourbon and come down from the creation, that's my payoff. A man I truly respect (not in the music biz) has told me repeatedly, "You have to love the process". I love the process. I don't just love the process, the process is what I do. It is what I specialize in. It is my job to make sure the band/artist is going through the process the right way.
The right way? It just happens. You can feel it. It's like a relationship. When it feels right, do it. Do it over and over again for as long as it feels good. Make it feel as good as you possibly can. Because once you release it, you never get it back. You can't unring a bell.