Seneca travels to cure his ailing body. This gives him an opportunity to reflect on people who travel yet remain discontent.
Regarding old age and the preservation of life, he writes,
the good man should not live as long as it pleases him, but as long as he ought. ... It gives proof of a great heart to return to life for the sake of others ... the greatest advantage of old age is the opportunity to be more negligent regarding self-preservation and to use life more adventurously.
Socrates is reported to have replied, when a certain person complained of having received no benefit from his travels: "It serves you right! You travelled in your own company!"
Living philosophically allows you to enjoy your travels. If you are not content with yourself, it does not matter where you are. Philosophy teaches you to have the good personality.
If you would escape your troubles, you need not another place but another personality.
If you would be content, enjoy what is in the present. But do not cling.
Regard everything that pleases you as if it were a flourishing plant; make the most of it while it is in leaf, for different plants at different seasons must fall and die.
The act of travelling or going on vacation does not solve root cause issues.
Travelling cannot give us judgment, or shake off our errors; it merely holds our attention for a moment by a certain novelty, as children pause to wonder at something unfamiliar.
The time spent learning and applying philosophy will go a long way to relieve you of your discontent.
We ought rather to spend our time in study, and to cultivate those who are masters of wisdom, learning something which has been investigated, but not settled. ... as long as you are ignorant of what you should avoid or seek, or of what is necessary or superfluous, or of what is right or wrong, you will not be travelling, but merely wandering.
Wherever you go, your ailments will follow unless you apply remedies to them.
That from which you are running, is within you. Accordingly, reform your own self, get the burden off your own shoulders, and keep within safe limits the cravings which ought to be removed. ... If you would be stripped of your faults leave far behind you the patterns of the faults.
Nature would have us live according to Nature. Therefore, she has blessed us with the necessary tools to pursue this goal. It is a lofty goal; one with which many disagree - aligning your will with 'the soul of the universe' - but not the Stoics.
Nature has brought us forth brave of spirit, and, as she has implanted in certain animals a spirit of ferocity, in others craft, in others terror, so she has gifted us with an aspiring and lofty spirit, which prompts us to seek a life of the greatest honour, and not of the greatest security, that most resembles the soul of the universe.
Reflect on the causes of your fears and anxieties. Reflect that it is your judgement that is the cause. These things which you think you fear, are not really frightening.
Shapes dread to look upon, of toil or death are not in the least dreadful, if one is able to look upon them with unflinching gaze, and is able to pierce the shadows.
History has given us sages to look towards as examples of equanimity. Whatever happened to them, they remained unperturbed.
Take the time to read Seneca's reflection on Socrates. This is what we are to aim for by living philosophically. I've italicized that parts which stand out to me, as I read this passage.
a long-suffering old man, who was sea-tossed amid every hardship and yet was unconquered both by poverty (which his troubles at home made more burdensome) and by toil, including the drudgery of military service. He was much tried at home, whether we think of his wife, a woman of rough manners and shrewish tongue, or of the children whose intractability showed them to be more like their mother than their father. And if you consider the facts, he lived either in time of war, or under tyrants, or under a democracy, which is more cruel than wars and tyrants. The war lasted for twenty-seven years; then the state became the victim of the Thirty Tyrants, of whom many were his personal enemies. At the last came that climax of condemnation under the gravest of charges: they accused him of disturbing the state religion and corrupting the youth, for they declared that he had influenced the youth to defy the gods, to defy the council, and to defy the state in general. Next came the prison, and the cup of poison. But all these measures changed the soul of Socrates so little that they did not even change his features. What wonderful and rare distinction! He maintained this attitude up to the very end, and no man ever saw Socrates too much elated or too much depressed. Amid all the disturbance of Fortune, he was undisturbed.
Seneca then reflects on Cato.
His whole life was passed either in civil warfare, or under a political regime which was soon to breed civil war. ... No one ever saw Cato change, no matter how often the state changed: he kept himself the same in all circumstances – in the praetorship, in defeat, under accusation, in his province, on the platform, in the army, in death.
And this is the vote which he casts concerning them both: "If Caesar wins, I slay myself; if Pompey, I go into exile." What was there for a man to fear who, whether in defeat or in victory, had assigned to himself a doom which might have been assigned to him by his enemies in their utmost rage? So he died by his own decision. You see that man can endure toil: Cato, on foot, led an army through African deserts. You see that thirst can be endured: he marched over sun-baked hills, dragging the remains of a beaten army and with no train of supplies, undergoing lack of water and wearing a heavy suit of armour; always the last to drink of the few springs which they chanced to find. You see that honour, and dishonour too, can be despised: for they report that on the very day when Cato was defeated at the elections, he played a game of ball. You see also that man can be free from fear of those above him in rank: for Cato attacked Caesar and Pompey simultaneously, at a time when none dared fall foul of the one without endeavouring to oblige the other. You see that death can be scorned as well as exile: Cato inflicted exile upon himself and finally death, and war all the while.