I love working
Coming back from a week of traveling, being in nature, and pretty much not working at all, I am realizing how much I love working - understanding new concepts, creating something new, deeply engaging with a problem and thinking it through.
Sitting in the train on the way back, already working on a few things and feeling the excitement of the upcoming tasks feels fulfilling.
Malcolm Gladwell writes in his book Outliers: "Autonomy, complexity, and a connection between effort and reward are the three qualities that work has to have if it is to be satisfying. [...] Work that fulfills those three criteria is meaningful."
I would add a forth, less tangible and very personal dimension: spark. The work we do should continuously ignite curiosity and passion, keeping us energized and deeply involved over time.
For me, all of this is currently fulfilled, and I'll be giving my best that it stays that way.