Forget spoon theory for a minute. Just think of it like money.

Some people have enough money that they never have to worry about being able to do anything. They can afford whatever whims they have.

Some people have good enough health that they can do whatever they want to whenever they want to. They can stay up all night and be fine the next day. They can go hiking or skydiving or run a marathon and they're fine.

Most people have a limited budget. They can do those things, but they need to prepare for them. If they don't prepare for something, they'll have less money later and will need to save up again before they can do something else, but they'll be fine.

Some people live paycheck to paycheck and have a lot of trouble saving up money, especially for fun things. They have to budget all of their money into necessities, like food and housing -- like being able to take a shower or go to the store.

They can push their budget to allow for fun things, but if they're not careful and don't keep close track of everything, they'll overspend and won't be able to do the necessary things anymore

Some people don't have enough money to do the necessary things. They need help to do basic things like bathing. They're housebound or bedbound and barely have enough to make it through the day, if even that

Some people have an income that fluctuates between one of these and another. They can do something one month and then next month they won't be able to

You can "borrow spoons against future-you", just like you can take out a loan or borrow money from someone you know. But that money has to come from somewhere, and you have to pay it back, often with interest.

I can push myself to do something today that takes up more spoons than I actually have, but I will have to spend a lot of time recovering from it when I'm done, and won't be able to do that again for a while

Do it too often and no one will loan me money anymore. Future-me won't have any spoons left for me to borrow.

I talk about budgeting for "fun" things here, but everyone who's ever struggled with money knows that sometimes you just can't afford to do that super important and not-at-all fun thing. Your car needs a repair, or the roof's leaking, or your job is making you travel somewhere

So you borrow for it, and things are tight for a while. And for a lot of people, then everything's fine -- but if it's something you have to do again and again and again? If you're borrowing money or spoons every month or every week or every day?

It gets unsustainable real fast, and you have to admit that you just can't do it.

And that's why some disabled people can do things, sometimes, that they wouldn't be able to normally but still can't hold down a job.