Adulthood is realizing,
that there are no grown-ups
and everyone is winging it
adult ['ædʌlt] grown up - взрослый
Adulthood ['ædʌlthud] взрослость
realize [ˈrɪəlaɪz] понимать, осознавать
to wing [wɪŋ] импровизировать (To do something with no preparation)
just wing it - просто импровизируй. там разберемся