spon·ta·ne·i·ty /ˌspɑːn.tənˈeɪ.ə.t̬i/
Noun
the quality of acting on the spur of the moment, without prior planning
"Spontaneity, the hallmark of childhood, is well worth cultivating to counteract the rigidity that may otherwise set in as we grow older."
- Gail Sheehy (1936 - 2020)