Iron rusts from disuse; water loses its purity from stagnation... even so does inaction sap the vigor of the mind.
Leonardo da VinciPutting your hand into a river, you simultaneously touch the last of what is passing and the first of what is coming.
Leonardo da VinciFor once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return.
Leonardo da Vinci