[A mathematician is a] scientist who can figure out anything except such simple things as squaring the circle and trisecting an angle.
Children grow out of childhood, but parents never grow out of parenthood.
A special skill, like speaking several languages, or keeping your mouth shut in one.
The three chief causes of divorce are men, women, and marriage.
The lecturer who is full of his subject is usually very slow in emptying himself.
All work and no pay makes a housewife.