You're only young once, but you can be immature forever. Germaine Greer
You can only be young once. But you can always be immature. Dave Barry
It is so easy to be immature. If I have a book to serve as my understanding, a pastor to serve as my conscience, a physician to determine my diet for me, and so on, I need not exert myself at all. I need not think, if only I can pay: others will readily undertake the irksome work for me. Immanuel Kant
I am too childlike to be immature. Lee Siegel