Tri Girl - I'm in the same boat, I live very simply and with minimal clutter... my SO is a pack rat. She's gotten much better over the years but it's still an issue for us.

We're prepping for our next transition and have been inventorying everything we own, I'll suggest selling the chairs in the living room and she'll agree (we won't have room when we move), then she backtracks and suggests we put them in storage. As you said, it's maddening.