There are only two types of accountants in the world....

There are more than two types of aphorisms along these lines. Here are some of my faves. 

There are only three types of accountants in the world.... 

....Those who can count and those who can't.

There are only 10 types of accountants in the world.... 

.... Those who understand binary and those who don't 

There are only two types of accountants in the world.... .

...Those who walk into a room and say, ‘There you are!’ – and those who say, ‘Here I am!’ ” (original credited to Abigail Van Buren) 

There are only two types of accountants in the world.... 

....Those who can extrapolate from incomplete data

Any more?