Odysseus' return wasn't easy!
For the hero of the monomyth, one of the last and most important parts of their quest is returning to their world after facing the road of trials and reaching apotheosis, retaining the wisdom they have gained along their way to integrate it into their old way of life. The true test of their success lies in how well they are able to share their newfound wisdom with the rest of the world. However much they dislike it, however much they would like to stay in the sanctuary of cosmic unity in the underworld, the hero mus return to the world of common day and must accept it as real.
Professor Joseph Campbell: " The first problem of the returning hero is to accept as real, after an experience of the soul-satisfying vision of fulfillment, the passing joys and sorrows, banalities and noisy obscenities of life. Why re-enter such a world? Why attempt to make plausible, or even interesting, to men and women consumed with passion, the experience of transcendental bliss? As dreams that were momentous by night may seem simply silly in the light of day, so the poet and the prophet can discover themselves playing the idiot before a jury of sober eyes. The easy thing is to commit the whole community to the devil and retire again into the heavenly rock dwelling, close the door, and make it fast. But if some spiritual obstetrician has drawn the shimenawa across the retreat, then the work of representing eternity in time, and perceiving in time eternity, cannot be avoided."
The first threshold the hero crossed, at the beginning of their adventure, was a symbolic death from their home life. This final transition, the return threshold, is a symbolic rebirth back into the 'real world'. The hero's task now is to try and make other people understand what they have just gone through so much to learn. This is very difficult, though, as the only way to do this is usually with words, which are often insufficient in explaining the world beyond form and language, the eternal always. Many people will have a hard time accepting what the hero has to tell them about the nature of reality. At best, they will think the hero is mad, at worst, that he is malignant.
The hero must watch their ego at this point. No matter what transcendent experiences they have had, one cannot communicate to others from an elevated state beyond the real-world concerns of most people: earning a living, staying healthy, inter-personal relationships. A dualistic state of mind is again needed so that the hero can see things from both their old and new views of the world, in order to bridge those worlds and explain their interrelation to the uninitiated.
There is a danger that the hero may get pulled back into the physical world and lose the power they have earned on their journey. The hero knows now that all is illusion, yet they must exist on the physical plane, with its war and sickness, hatred and greed. The real test lies in striding both worlds successfully keeping the eye on the eternal and directing others' vision towards it. The hero may now have difficulty in seeing what it was about their old life that was so bad, and risk the danger of falling back into old patterns. Neither the old life or the new one will do in and of themselves: the true hero is the master of both worlds.
For the audience, the crossing of the return threshold is a final relief after the trials and tribulations of the adventure. The final threshold creates closure of the story started in crossing of the first threshold. The return to the safe place of known forms and motivations is a relief both for the hero of the story and the reader. The most trying action has run its course, and rights have been wronged. Like coming home at the end of a long day, the crossing of the return threshold is where anxieties cease and doubts and truths are reaffirmed. We all pass through innumerable thresholds daily, in and out of fear and knowledge. The thresholds are the gates of experience, through which we quest-ion and get answers to the mysteries of life.