There are 365 days in a year. Assuming (optimistically) I am healthy and live for 50 more years, I have 18,250 days left in my life (I die at 87, in this calculation). I work a full time job and commute which means I really can only work on music on the weekends. I have roughly 5,214 weekend days left. That’s 125,136 hours. On average I probably work 4-6 hours per weekend day on music. Assuming I can keep this up for the rest of my life (again, very optimistically), I have 20,856 hours left of music-making. That’s 869 days. It’s all over the place, but let’s say the average amount of time it takes to finish a song, from first idea to completed master, is 20 days. At this current rate, I can finish 43.45 songs. Then I die. Conclusions: I need to be more efficient at song-making, or use more time.
Of course, making music is the fun part, and the goal isn't to simply finish songs. But it'd be nice to finish one now and then.