Hi Inma,
The translation is given as “every journey has become a thrilling (?) adventure.” If convertirse (en) is the verb of choice here for “become”, would it have been better to give a different translation perhaps “every journey has turned into a thrilling adventure.”
It strikes me that “convertirse en” just doesn’t fit with your lesson where you say that it is used to describe “A radical change in personality or profession,” and is interchangeable with “hacerse” in that regard. Hence a different translation would have steered me towards either “convertirse en” or “volverse” [which is what I chose]. That said, your lessons on this topic deal with people becoming a certain way, rather than situations changing. Perhaps the guidance for the former cannot be carried through to the latter. Can you clarify this in any way? Saludos. John