Mood up

Second exam today. Went better - I couldn't do two of the short questions, but I did the two long ones and I think I got them right. (Managed to detect an error in the second one when I said -1/-1 = -1...) Hardly any time to check, everyone thinks we don't have enough time.
Am a little worried that not doing so good on an exam plunged me into a fit of angst and depression that lasted for twenty-four hours and then doing good on this one immediately lifted me. I do not feel my mood should be so dependent on maths...