In Paulo Coelho's The Alchemist, regarding the statement "To achieve great happiness you must be willing to travel to far off places," I would suggest that this is true on several levels.
In life, on a literal basis, we often are asked to "go the distance," or take a road that requires more than we might want to give. This is the case when someone (especially in this economy) takes a job and has to travel so far that it's hardly worth the gas, or has to work in a job he's overqualified for. Literally, we may have to work harder for something than we might want to when we believe that it shouldn't take so much effort.
We see this in The Alchemist. When Santiago loses everything, he believes that the only thing to do is get a job, make some money, buy some sheep, and return to his old life. After he loses everything, this would be a perfect time to give up his dream: he sees the long months ahead that he must work before he will have enough money to go home. The far off place to which Santiago must travel is the future—with what he sees as a slow passage of time. He is being asked to do something that should not be necessary, and the completion of this task will require Santiago to be patient.
From another perspective, a person may see that "far off place" as a place of belief, trust, faith, etc. Someone might believe that before he/she can fall in love, trust someone, or exercise any kind of faith that he/she must make a metaphorical journey. In Coelho's novel, the trust that Santiago must learn to act upon is a belief in what the King of Salem tells him: he must travel to a distant place believing that all will work out, without having a companion or a sense of certainty that he will succeed. This is a far off place for Santiago, figuratively.
Sometimes the far-off place is reaching what seems to be an impossible goal. We are challenged by life to attempt to do something that we may feel we can never achieve. A willingness to try takes us at least halfway to our goal. Later we may see that what stood in our way was simply our own doubts and fears. When the alchemist tells the soldiers that Santiago can turn himself into the wind, the boy reacts with horror, sure that the old man has condemned him to death. It is only after doing all he can to achieve his wish that he realizes that moving forward, rather than turning away in failure, allowed him to be successful. The ability was there, but Santiago had to learn to see it for himself.