John's journey is so unusual precisely because it breaks so many of the taboos that feature as part of his and his tribes life. Note what his father says to John after John has had his dream of going to the Place of the Gods as part of his initiation ritual:
"It is forbidden to travel east. It is forbidden to cross the river. It is forbidden to go to the Place of the Gods. All these things are forbidden."
The phrase "It is forbidden" is used a lot in the first paragraph to highlight the way that we are presented with a society that is ruled by fear and tradition. John's dream points towards his journey into realms in which no one else has entered for a very long time, precisely because of the taboos surrounding these locations, but he knows that he must be obedient to the dream he had, whatever awaits him. Thus John's journey is so unusual because of his destination and the way that it is completely forbidden for him or anyone else to go there.