ignorance

ignorance /ˈɪgnərəns/ noun
ignorance
/ˈɪgnərəns/
noun
Britannica Dictionary definition of IGNORANCE
: a lack of knowledge, understanding, or education : the state of being ignorant
[noncount]
— often + of
[singular]

ignorance is bliss

— used to say that a person who does not know about a problem does not worry about it