I have a little shadow that goes in and out with me,
And what can be the use of him is more than I can see.
He is very, very like me from the heels up to the head;
And I see him jump before me, when I jump into my bed.

Robert Louis Stevenson (1850–1894) Scottish essayist, novelist, poet

Poem (1885), “My Shadow,” st. 1, A Child’s Garden of Verses
    (Source)