The saying presents learning as an activity that sustains rather than depletes the mind. Its central idea is that intellectual effort can generate further curiosity, understanding and engagement, rather than simply consuming a limited supply of mental energy. Learning is therefore framed as a continuing process of development.

The statement can be applied to education and lifelong study, particularly where learning is understood as exploration rather than obligation. It suggests that sustained curiosity can keep the mind active and open to new ideas, even though concentration and study can still be tiring in practical terms.

The quotation is widely attributed to Leonardo da Vinci, but there is no reliable primary or secondary source establishing that he wrote or said it. It should therefore be treated as an uncertain or unsupported attribution rather than as a securely documented statement by Leonardo.