Since this is Fake Love Extended Ver., my theory will be an extended version as well. Please head over to my Fake Love Theory here. 

As I said before, all the boys are manifestations of one person at each stage of life, exposed to a particular kind of evil, and must overcome them. Jungkook did not have a fear to trade in because we know from WINGS and Demian that he is the persona of a boy naive to the evils of the world. Therefore, he receives a key instead that would start his journey to maturity by going through each persona, which are the other members, exposing himself to evil.

After Jungkook finally overcomes the maze, he ends up in Jin’s room after the explosion. He sees the hooded figure, which we now know is himself. 

What is interesting is that in the teaser 1 of Fake Love, they were exchanging their fears for positivity symbolized by the items from WINGS and Highlight Reels. Now in the extended version, they showed us that the members have two selves. One is their true self, the one who trades in the item, and one is the fake self, who is behind the mask or the shopkeeper. So they were basically doing a transaction between themselves, signifying the internal bargain with themselves.

As I said before, Jungkook finds the “answer” when he found the room reminiscent of the beach, symbolized by the sand and the water, that the members wanted to meet each other again eventually according to the HYYH notes. This scene symbolizes Jungkook reaching maturity after exposure to evil. 

The reason why the scene of Jungkook joining the other members keeps on getting paralleled is because BigHit wants emphasize the fact that the members are all manifestations of each other and Jungkook is the beginning of a boy’s life. Jin represents the PRESENT persona of a boys life and all the other members represent personas in the middle. This is also why in other music videos, it’s always Jungkook and Jin who are isolated as the protagonists. (Side note: that’s also why if you review the Fake Love choreography, Jungkook keeps mirroring the other members such as J-hope, RM, V, and Jin.)

The scene in the WINGS VCR:

The scene in the DNA VCR:

Finally, the scene in Fake Love Extended Version:

After Jungkook enters the “secret passage” is when he matures and this is also symbolic of when he creates or finds his own fake self in the room. We all create fake selves in some shape or form in order to mature and find ourselves (That is why adolescents explore many identities and have identity confusion at that age of maturity). Jungkook then goes in and joins the other fake selves of the other members that they created in an attempt to gain love in Highlight Reels according to BigHit. And this is why they get crushed at the end. They voluntarily ended their fake selves in order to find real love.