Actually the interesting thing about the brain is, that you might think you are not capable, but usually this comes at the end of your comfort zone. But lots of interesting things can happen outside of one's comfort zone.
I learned this via workout. When I feel I can't do more pushups, it is not really my boundary, and if I do one more, that achieves more, than the pushups I can easily do.
I meant something like this.
But of course, be aware of burnout!
Cheers! π€