know one's own mind

Verb

know one's own mind (third-person singular simple present knows one's own mind, present participle knowing one's own mind, simple past knew one's own mind, past participle known one's own mind)

1. (idiomatic) To clearly understand one's own feelings, intentions, preferences, etc; to know precisely what one wants; to be decisive or determined.
   • Demi knew his own mind, however, and tranquilly carried out his plans, unmoved by the tongues of the anxious mammas or the jokes of his mates.1886, Louisa M[ay] Alcott, chapter 1, in Jo’s Boys, and How They Turned Out. A Sequel to “Little Men.”, Boston, Mass.: Roberts Brothers, →OCLC
   • He sadly wants strength of purpose; and, like weak men in general, he only knows his own mind when a resolute friend takes him in hand and guides him.1889, Wilkie Collins, chapter 54, in The Legacy of Cain