amnesiac
amnesic
incognizant
unaware
Lethean
a stranger to
absentminded
airy
aloof
amnestic
apathetic
asleep
ataractic
blase
blind to
blocked
bored
careless
casual
caught napping
converted
cursory
dead to
deaf to
degage
detached
devil-may-care
disinterested
dispassionate
disregardant
disregardful
distant
distracted
distrait
easygoing
flippant
forgetful
forgetting
free and easy
heedless
impassive
impercipient
in ignorance of
inadvertent
inattentive
inclined to forget
inconsiderate
incurious
indifferent
inexcitable
absent-minded
deaf
devoid
engrossed
impervious
insensible
mindful
negligent
oblivious
unable
unafraid
uncalled
unconcerned
unconvinced
uneventful
unimpressed
unjustified
unmoved
unresponsive
unscathed
valueless