An addictive subject, where succeeding at solving one of its problems, increases your desire to solve more and more.
But...
It is also a depressant, where failing at solving one of its problems, gets you
depressed and lowers your brain activity causing you to feel
dumb.
So take
care people...
Michael: Hey man, what are you doing?
George: Solving some math problems.
Michael: You need to cut off on mathematics man or we'll have
send you to rehabilitation.