there's probably some cost to having a bunch of unfinished projects occupy my mental bandwidth but I think there are some benefits:

  - having unfinished projects gives my mind a comfortable place to go think itself out when I'm tired and need to sleep.
  - each project doubles as a kind of lookout tower providing some perspective on other related projects or relevant technologies, and this keeps me interested in paying attention to new developments in non-superficial ways.
  - every once in while a spark of motivation will appear for a project I haven't touched in years and it'll be something I recently learned backpropagating constructively, tightening the whole mess up a bit and helping me retain it all.