said "eh, not today brain, not today" and got up to go for a walk. Was I cured? Of course not, but I 100% know I felt WAY better than me being in bed all day crying because I'm listening to nothingness in my head.
I only wanted to comment that this is a more realistic example for most people, than your example of getting up, putting on lipstick, and going to lunch.
Emotional capacity is an important concept; it speaks to identifying what an individual can tolerate, and let's them set realistic, achievable goals.
Just as you wrote above - on a very bad day, I can consider it a victory if I get up, have some coffee, and go for a walk around the block. That's actually ambitious for me, because of various problems I have being outside - but, I can achieve it, and can appreciate that I met a goal.
On medium bad days, going out in public is a reasonable goal I can set for myself.
Everyone's capacity is different. It's actually damaging to set a goal that is at the extreme end of your capacity, because you will create more stress, not less. I used to do that. On the worst of days, I would push myself the hardest, to try and do a 'perfect' day: get up, clean the apartment, dress really well, go to work, be the friendliest person there, go to the gym, run errands...all the while telling myself I was a failure if I couldn't just be normal despite my depression. About 3 days of that, and then I'd hit a physical crash where I was unable to move for a few days.
Anyway, that was a sidebar - I only wanted to identify the differences in scale, when setting goals, and how what matters is trying to be realistic about what we can do, so we can actually achieve it.
For some people on some days, just getting up can be a major victory all its own. A great thing I learned in a PHP was about setting five goals for the day - and they might be get up, eat breakfast, get 30 minutes of physical activity, do 30 minutes of something for myself (read, knit, puzzle, whatever), and pay one bill. If that's what you can do that day, make that plan and do it. With permission to take breaks as often as you need. Invariably, I'd feel a bit better by the end of the day, and much less guilt about all the things I 'should' get done (if that makes sense).
I'm not saying you don't know these things,
@ShamrockChalk - I'm only adding to the concept you are speaking of, in more detail.