The phrase "addressed oneself to" refers to directing one's attention or efforts towards a particular task, goal or person. Antonyms for this phrase could include avoiding, ignoring, neglecting, or disregarding. If one were to avoid or ignore something, they would not be directing their attention or effort towards it. Neglect would mean that something has been left unattended or uncared for. Disregarding would mean that something has been deemed unimportant or not worth addressing. These antonyms indicate a lack of attention or effort given to a particular task or goal, as opposed to the intentional focus implied by "addressed oneself to.