The evening being come, I return home and go to my study; at
the entrance I pull off my peasant-clothes, covered with dust and dirt,
and put on my noble court dress, and thus becomingly re-clothed I
pass into the ancient courts of the men of old, where, being lovingly
received by them, I am fed with that food which is mine alone; where I
do not hesitate to speak with them, and to ask for the reason of their
actions, and they in their benignity answer me; and for four hours I
feel no weariness, I forget every trouble, poverty does not dismay,
death does not terrify me; I am possessed entirely by those great men.
And because Dante says:

Knowledge doth come of learning well retained,
Unfruitful else.

Niccolò Machiavelli to Francesco Vettori, dated 13th December 1513.