When do we stop being children? Never is the answer. We may attain our eighteenth and twenty first birthdays and various big, "o's" thereafter, but for most of us the desire to be children does not disappear. We want to have someone to refer to, someone who will make decisions for us, someone who will protect us from the vagaries of life/existence.
Logically you may know that roles have reversed and that your parents are now the dependants, but the yearning for support and even approval does not disappear. Even the death of a parent does not give solidity of resolve and decision, it merely highlights the lacunae that human life throws at us. Adulthood, or more accurately age, is in reality a series of decades when loss is the predominant feature. Loss of looks; loss of fitness; loss of parents; loss of friends; loss of mobility; loss of cognitive powers. And finally? That's it, you have got it.
The causa causans of life has a tendency to cover itself in camouflage clothing.