I have a side project[1] that has made me $0 over the past 8 years. It's not well known and few, if any, other developers make use of it. I still work on it most days because I enjoy working on it.

I assume I'm part of the majority. Thinking otherwise would damage my self-belief and self-confidence.

[1] - https://github.com/KaliedaRik/Scrawl-canvas