Antonyms for the phrase "concerned oneself with" include disregarded, ignored, overlooked or neglected. These antonyms suggest a lack of interest or attention towards a particular issue or matter. The opposite of being concerned about something is to have a careless or apathetic attitude towards it. To ignore or neglect something can lead to negative consequences, especially in important aspects of life such as relationships, career, or health. Thus, it is essential to be mindful and attentive, to take proactive steps towards addressing issues and matters that require attention, rather than disregarding or overlooking them.