Old age overtakes them while they are still mentally childish, and they face it unprepared and unarmed. For they have made no provision for it, stumbling upon it suddenly and unawares, and without realizing that it was approaching day by day. Just as travellers are beguiled by conversation or reading or some profound meditation, and find they have arrived at their destination before they knew they were approaching it; so it is with this unceasing and extremely fast-moving journey of life, which waking or sleeping we make at the same pace–the preoccupied become aware of it only when it is over.

—Seneca, On the Shortness of Life: Life Is Long if You Know How to Use It