Laudator Temporis Acti

In his Epistulae Morales 9.18-19, Seneca tells this story about the Greek philosopher Stilpon (c. 380-300 B.C.):

For when his homeland was captured, his children lost, his wife lost, and he was walking away from the public conflagration by himself and yet unconcerned, Demetrius (whose nickname was Poliorcetes, after his destruction of cities) asked him if he had lost anything. He said, "All my goods are with me." Behold a strong and stalwart man! He was victorious over the victory of his enemy. "I have lost nothing," he said: he made Demetrius doubt whether he had actually conquered. "All of my goods are with me": justice, virtue, prudence, the very fact that he considered nothing good that could be snatched away.

Hic enim capta patria, amissis liberis, amissa uxore, cum ex incendio publico solus et tamen beatus exiret, interroganti Demetrio, cui cognomen ab exitio urbium Poliorcetes fuit, num quid perdidisset, 'omnia' inquit 'bona mea mecum sunt'. Ecce vir fortis ac strenuus! ipsam hostis sui victoriam vicit. 'Nihil' inquit 'perdidi': dubitare illum coegit an vicisset. 'Omnia mea mecum sunt': iustitia, virtus, prudentia, hoc ipsum, nihil bonum putare quod eripi possit.

Cicero, in his Paradoxa Stoicorum 1.1.8, tells a very similar story about Bias, one of the "seven sages" of ancient Greece:

I shall also often praise that famous sage, Bias I think, who is included among the seven. When the enemy had captured his homeland and others were fleeing in such a way as to carry many of their possessions with them, and he was told by someone to do likewise, he said, "I am indeed doing it; for I am carrying all my things with me."

nec non saepe laudabo sapientem illum, Biantem, ut opinor, qui numeratur in septem; cuius quom patriam Prienam cepisset hostis ceterique ita fugerent, ut multa de suis rebus asportarent, cum esset admonitus a quodam, ut idem ipse faceret, 'Ego vero', inquit, 'facio; nam omnia mecum porto mea.'

Valerius Maximus 7.2.ext.3 seems to follow and elaborate on Cicero:

When enemies had invaded his homeland Priene and all (at least those whom the savagery of war had permitted to get away safe) were fleeing loaded with the weight of their precious possessions, Bias was asked why he was carrying none of his goods with him. He said, "Indeed, all my goods I carry with me," for he was carrying them in his heart, not on his shoulders, things not to be seen by the eyes but to be valued by the spirit.

Bias autem, cum patriam eius Prienen hostes invasissent, omnibus, quos modo saevitia belli incolumes abire passa fuerat, pretiosarum rerum pondere onustis fugientibus interrogatus quid ita nihil ex bonis suis secum ferret 'ego vero' inquit 'bona <omnia> mea mecum porto': pectore enim illa gestabat, non humeris, nec oculis visenda, sed aestimanda animo.

bona <omnia> mea mecum Gertz, omnia om. A Halm, bona mecum omnia Par.

According to Henry David Thoreau in The Maine Woods, his Indian guide Joe Polis literally carried all of his possessions, or at least all necessary ones, with him:

I observed that he wore a cotton shirt, originally white, a greenish flannel one over it, but no waistcoat, flannel drawers, and strong linen or duck pants, which also had been white, blue woollen stockings, cowhide boots, and a Kossuth hat. He carried no change of clothing, but putting on a stout, thick jacket, which he laid aside in the canoe, and seizing a full-sized axe, his gun and ammunition, and a blanket, which would do for a sail or knapsack, if wanted, and strapping on his belt, which contained a large sheath-knife, he walked off at once, ready to be gone all summer. This looked very independent; a few simple and effective tools, and no India-rubber clothing. He was always the first ready to start in the morning, and if it had not held some of our property would not have been obliged to roll up his blanket. Instead of carrying a large bundle of his own extra clothing, etc., he brought back the great-coats of moose tied up in his blanket. I found that his outfit was the result of a long experience, and in the main was hardly to be improved on, unless by washing or an extra shirt.