26. "What Took You So Long?"
The very first time players meet Mama in the opening hour of the game, she asks Sam, "What took you so long?". This is of course an hilariously unsubtle reference to a Hideo Kojima meme that was born from Metal Gear Solid V: Ground Zeroes.
You see, Kojima himself appears in Ground Zeroes as an NPC during a Side Ops mission, and upon rescuing him, he'll ask Snake, "What took you so long?"
With the phrase quickly going viral, it was just a matter of time before Kojima returned to it.
Death Stranding also features numerous references to people being kept waiting, surely a nod to Snake's infamous, "Kept you waiting, huh?" quip from the start of Metal Gear Solid V: The Phantom Pain.