Permutations.
N! One to change the light bulb, and n-1 to display stereotypical behavioral traits of X!
X-Men
Neither of them are ever right.
Don't do it! You have so much potential!"
Because they can only count to 3.
Because if they count one more it would be 2gross to continue.
L'Hospital.
What do mathematicians and dancers have in common? They both have algorhythm.