Zach Dicklin, I feel your pain. I too have so many projects that I can’t keep track. I’ve never made any real money from any of them but they have all helped me grow in some way.
I’m also at this crossroads with how to approach future side projects–it’s hard. I even created a priority matrix to help guide my decision making. It’s helping a little. For me, I can’t really stop my brain from working this way. I see problems or get an idea, I get curious and I’m off to the races (inside my brain) solving, tinkering and making. I’ve resolved that I shouldn’t fight these impulses.
I do need to be more aware of how I spend my energy and I saw a ton of great ideas in the other comments here. Don’t ever think of your past projects as a waste of time. Failure is not a dirty word. Failure is learning. Every smart person will tell you (every smart book about entrepreneurship will as well) that the big ideas come after many, many missteps. We just don’t hear about those as much.
Thanks for writing this and good luck.