Hi, so while I was doing my master's degree a professor really liked my work and suggested I further develop the coursework within my dissertation. Which would then provide me with the opportunity to apply for a PhD with that same supervisor.
And I did, because actually I do love to do research and to study.

Currently, I'm in my 4 month of the PhD, and my supervisor told me that from September onwards he is going to start working for another university in a country in the other side of the globe. And because he could only choose one student, he asked if I would want to go with him. Which I do really want. Even though I would be in one of the best universities in the sector, I don't really know if it is the best strategy professionally.
Do you have any stories, or suggestion?

I'm sorry but I don't really understand your concern.Are you concerned about moving abroad? This is of course a massive consideration, and only you will know if it is something you would like to try. But beyond that what is your concern? All that you have stated sounds extremely positive to me!