This might look ordinary in the beginning, but as u keep on watching it, u'll realise that IU entering the train w/ a lot of people in it symbolizes how she entered the kpop industry as a soloist. See how the dancers are grouped & seemed to know each other while she's going solo?

But as her journey inside the train continues, you'll see that she's partying like she's one of them.. Trying to keep up with how their world works so she could fit in, and wouldn't fall out of it. This symbolizes her early yrs in the industry

As the train exits the tunnel, she's seen having a fight just to get that single cookie in the end. The price of getting what you want is to fight your own battles alone.. You had to experience pain first, before getting your price in the end. This was during her Chat-Shire Era..

And as she succeeds to stand her ground and get what she wants, she was able to fully express herself during her journey.. However even tho she already has everything, she still feels something's missing.. Thus, this scene from Celebrity MV represents her Palette to Love Poem Era

She had to face herself so she would know how to fill that emptiness.. She gained a lot during one era, and lost a lot as well during another.. But she never stopped her journey, and gambled one more time even though she knows she may lose again..

Fame, money, and popularity. She got all this, as she fight & gambled her way up to where she is now, but she knows that there's no guarantee that she'll always have everything. Tho she knows as well that the only way for her to enjoy & keep everything is to love herself..

Removing her purple tinted glasses & burying it together with her diaries in a time capsule, symbolizes that she's ready to let go of the memories of her youth, and focus more on a brighter and more relaxed future ahead of her.

This time capsule represents her legacy...

So as she gets another chance to fight & gamble for another journey, She ended her twenties era with a glamorous & meaningful bow to all of the people who were always there for her and never left her side during her whole journey for the past 13 years..

... And start another journey as she enters her thirties

"Spring is short, but it comes again" - IU