Most definitely there is and it is real and tangible. Chemo is a systemic treatment that kills cells. Not just cancer cells but healthy cells as well including brain cells.
If you aren't already, become a list maker. Write down everything you need to remember. Stuff you need to do, appointments, etc. I even write myself a note when I am doing laundry so I won't forget to put it in the dryer for 2 days. I've even had to make myself a tickler file with when each monthly bill is due. I did that after the second time I ended up paying a late fee because I just forgot I hadn't paid it. And of course, always keep your lists in the same place. Doesn't do any good to make a list if you don't remember where you put the list.