In youth it is the outward aspect of things that most engages us; while in age, thought or reflection is the predominating quality of the mind. Hence, youth is the time for poetry, and age is more inclined to philosophy. In practical affairs it is the same: a man shapes his resolutions in youth more by the impression that the outward world makes upon him; whereas, when he is old, it is thought that determines his actions.

Parerga and Paralipomena (1851) - Counsels and Maxims