What should I do if my brain capacity is insufficient?

If the capacity is not enough, you'd better change it to a bigger one, or a chip, and keep it in your head all the time, preferably the one with super capacity. If you can, your brain capacity will not be the same as that of a small class, otherwise you will be more helpless and sometimes there is nothing you can do, so this is the only way. Don't be too small if you don't change it. After all, you are old, and you can only do this until you have a chance to change your head. If you don't mind, maybe you can't say a mechanical head.