The period of ordinary children is also called the golden age, where the time to learn is good at an early age. Sharing knowledge which in the study is easy to understand.
But for us as a human being mortal no age limit to continue learning. there is advice from the Prophet Muhammad SAW "Demanding knowledge from the womb to the grave" meaning that learning is not considered age, children, adolescents, adults, elderly all must learn. Because the more we get to something the more we know if we are still many that have not been understood.
Wassalam by @Cakrawala