Maybe it's time for a little math joke to help keep your spirits up:
What weighs 2000 lbs and grazes on the real line?
6 is afraid of 7, because 7 8 9... :-)
Today a co-worker of mine was telling us a joke he read on /r/meanjokes. It goes like this:
A physicist, an engineer, and a statistician all go out hunting together. They've all got their rifles and they stomp out into the woods to their favorite hunting stand and, lo and behold, there's a big moose just sitting out there, chomping some grass, waiting to be shot. The physicist does some calculations, gravity and velocity and all that, aims, fires. He misses 5m to the left. The engineer shoves him aside and says, "you forgot to take into account the wind!" He does some more calculations, aims, fires, and missed 5m to the right. Then the statistician says, "We got him!"
Cristina's reminds me of this one:
Mathematician: 3 is a prime, 5 is a prime, 7 is a prime, 9 is not a prime, 11 is a prime; so, some odd numbers greater than 1 are primes and some aren't.
Physicist: 3 is a prime, 5 is a prime, 7 is a prime, 9 is not a prime, 11 is a prime; that's 4 out of 5, so all odd numbers greater than 1 are primes.
Engineer: 3 is a prime, 5 is a prime, 7 is a prime, 9 is a prime, 11 is a prime...
Hint for Boris on the original riddle: think of an undecidable question.