My girlfriend is a genius. To do? No. Done!

Feeling overwhelmed with all that she did not do on her to-do list, my girlfriend started a DONE list. She just writes down all the things she’s done and feels good about it. I tried it and it’s great! Rather than looking at all the things I haven’t done, I look at what I have done. She joined a group where they share their "done" lists and keep each other accountable. Anyone is welcome to join: here. The change gamifies it enough that I want to add to the done list. Has anyone tried this?