You never can tell what your thoughts may do,
In bringing you hate or love,
For thoughts are things, and their airy wings
Are swifter than carrier doves.
They follow the law of the universe —
Each thing must create its kind,
And they speed o’er the track to bring you back
Whatever went out of your mind.

Ella Wheeler Wilcox (1850-1919) American author, poet, temperance advocate, spiritualist
Poem (1896), “You Never Can Tell,” st. 3, Custer and Other Poems
    (Source)