I don't know that this theoretical person has to be a genius in order to get stressed out from multi-tasking. It seems to me that all she has to be is a mother.
Once you've got kids, it's not just your own brain that you've got to keep happy. You've also got to nurture the talents and interests of a whole gaggle of little people (oh, yeah, and then there's feeding, clothing, soothing, cleaning, etc.). It's more than any one person can handle, and yet somehow, mothers manage to do it.
But sometimes, the cost of endless to-dos ends up hurting us more than helping us. In the words of Elton John, "There is more to do than can ever be done." (Sorry, can't help breaking out the Disney. I'm a mom).
So is the infinite nature of life's possibilities a blessing or a curse? Or both? When you see your day stretched before you, does it make you jump with excitement to fulfill your potential or want to crawl back in bed?