Un-done to-dos are like unread books on the shelf: they tell us who we wanted to be. The fact that we haven't done them tells us who we really are.
> "Your calendar never lies. All we have is our time. The way we spend our time _is_ our priorities, _is_ our 'strategy'. Your calendar knows what you really care about. Do you?"
--Tom Peters
Great point. A good reason to keep them around in some form, even if you only revisit them occasionally.
I had about 400 yet-to-be-completed items in my to-do list before I started afresh. Seemed like way too many. How about you?