oblivious

Synonyms: absent absentminded absorbed abstracted amnesic blind blundering careless deaf disregardful distracted dreamy forgetful forgetting gone heedless inattentive incognizant inconversant insensible neglectful negligent not all there out to lunch overlooking preoccupied regardless spacey strung out unacquainted unconcerned unconscious undiscerning unfamiliar uninformed uninstructed unknowing unmindful unnoticing unobservant unrecognizing unwitting zonked

Antonyms: aware concerned conscious mindful sensitive understanding