Split : Why the flowers? (Possible spoilers)

After reading numerous posts, I am beginning to understand the movie more and more, but why did Dennis place the flowers on the subway platform? Did he assume he was never gonna come back from being the beast?

I think it was some sort of symbolic gesture - Dennis was abdicating the control he & Patricia had. He knew the Beast didn't give a *bleep* about the flowers.
The way he laid them down was like he was placing them on a grave.
Death, rebirth, and whatever other metaphors you can think of.

It was just a gift for The Beast you stupid fck.

Haven't you ever given flowers to a date? Stop overthinking everything!

I thought it was a TRAIN platform. If i'm right here's my take: in one scene Dennis/Kevin say something like: My dad took a train a never came back. Since it has been revealed that its in he same universe as Unbreakable, I think that Dennis dad took the same train than the one that crashed in Unbreakable! Since that day his life was never the same. He suffered abuse from his mother that had to raise him alone. So the flowers is for his dad.

I might be looking too much into it. Lol

that's a good one I think you are totally right

SPOILERS!

I wondered about this too. When I saw the mid credits scene reveal I wondered if it possibly it could have tied into the train accident that was caused by Mister Glass. It would be a neat if they explored this with the Dunn character in another film. Maybe he placed the flowers there because he lost someone there. And that somehow lead to the evolution of The Beast and the formation of the Horde. Then maybe Mister Glass not only created Unbreakable (Dunn) but also the Horde.