If you are impatient, you don’t like to wait. Do you have a hard time teaching children new skills? Do grab the shoe and tie it yourself? You’re impatient.
Pent-up, antsy, restless, short-tempered, constantly checking the time — all of these are qualities of an impatient person. Patient comes from the Latin word patientem, meaning "to endure," but add the prefix im- and you get impatient — the inability to endure delays, mix-ups, people walking slowly, red lights. . .