Margot is way over my line.
I think for me, my time factors into the equation. If I think my time is worth more than the time it would take, for example, to wash a baggie with PB&J on it, then I'll save my time and not the baggie. This feeling of what's worth my time changes though - some days I'm more willing to do "X" than on other days.
Part of my struggle is that I am trying not to be surrounded by clutter, which means I can't save every last thing that might be useful to me another day.