I think that this is a very poor analogy. Your geography teacher was preparing you for EXAMS, not to travel the world. A better analogy would be an expedition guide - you would certainly hope they have been to the mountain/jungle you are going to, otherwise you would be in trouble.
A forex teacher is not teaching you for the purpose of passing forex exams, he is teaching you to make money in the REAL world.
A mentor needs to have a proven track record (over at least a year), be able to communicate why he traded the way he did, and it needs to be consistent.