As nouns the difference between insouciance and obliviousness
is that insouciance is carelessness, heedlessness, indifference, or casual unconcern while obliviousness is the characteristic of being oblivious.
insouciance
English
Noun
(-)
carelessness, heedlessness, indifference, or casual unconcern
nonchalance
Synonyms
* See also
obliviousness
English
Noun
(-)
The characteristic of being oblivious.