I actually managed to finish something - my Interstellar Rowing Simulator idea was sitting around for nearly a year, most of that time at the back corner of the "things on the go" cupboard. But now it is a reality!
One of those things that started as "can I figure out a way to make an effect/mechanic work?" and then drifted away until the jam came up and I remembered all the ideas I had for things to include, and now it has them all.