I guess it is second nature to me by now.
Violence and command weren't second nature to Darkyn; they were his first.
She never accommodated herself to the part she was called on to play during the Empire, and, though endowed with immense wealth and distinguished by the title of Madame Mere, lived mainly in retirement, and in the exercise of a strict domestic economy which her early privations had made a second nature to her, but which rendered her very unpopular in France and was displeasing to Napoleon.
It will become second nature to know when one lies to you.
But Cecil never developed that passionate aversion from decided measures which became a second nature to his mistress.