Even better. You've done the work, so your brain needs to be in a good state in order to retrieve the facts.
I wish I had known about yoga when I was at Uni. Another great thing to do is big big silent breaths (yep, breaths ;) ). Rotate your head around your neck until you find a stiff bit, and hold it, breathing in and out, deeply. Then move onto the next sore bit of your neck. Keep breathing. Don't think of anything but gooooooddd things...
