I don't remember how young I was. Much too young, I'm sure. I was probably caught between the trap of being a preschooler, an only child, having a "pack rat" father and a tidy mother, and never having been taught how to declutter and purge.
Inevitably I got to an age, probably 5 or 6 at most, where I was expected to have developed cleaning habits and skills in the face of a daunting amount of STUFF in a room much too large for someone my age to be fully in charge of.