Banksy says the quote at 13:14:

The origin might not be Banksy, though.

Here is an excerpt from Sum: Forty Tales from the Afterlives by David Eagleman:

There are three deaths: the first is when the body ceases to function. The second is when the body is consigned to the grave. The third is that moment, sometime in the future, when your name is spoken for the last time.

So you wait in this lobby until the third death. There are long tables with coffee, tea, and cookies – you can help yourself. There are people here from all around the world, and you can try to strike up a conversation with whomever you'd like. Just be aware that your conversation may be interrupted at any moment by the Callers, who call out your conversations partner's name to indicate there will never again be another remembrance of him by anyone on the Earth. Your partner slumps out, face like a shattered and re-glued plate, saddened even though he's kindly told by the Callers that he’s off to a better place. No one knows where that better place is, or what it offers, because no one exiting through that door has returned to tell us. Tragically, many people leave just as their loved ones arrive, since the loved ones were the only ones doing the remembering. We all wag our heads at that typical timing.

The whole place looks like an infinite airport waiting area, but the company is terrific. There are many famous people from history books here. If you get bored, you can strike out in any given direction, past aisles and aisles of seats. After many days of walking, you'll start to notice that people look different, and you'll hear the tones of foreign languages. People congregate amongst their own kind, and what one sees is the spontaneous emergence of territories that mirrors the way they were set up on the surface of the planet. With the exception of the oceans, you’re traversing a map of the Earth. Along with no oceans, there are no time zones either. No one sleeps here, even though they mostly wish they could. The place is evenly lit by fluorescent lights.

Not everyone is sad when the Callers shout out their names, when they call as though announcing the next flight departure. On the contrary, some people beg and plead when the Callers enter. They prostrate themselves at the Callers’ feet as the next names are read out. These are generally the folks who have been here a long time, too long, and especially those who are remembered for unfair reasons. For example, take the farmer over there, who drowned in a small river 200 years ago. Now his farm is the site of a small college, and the tour guides each week tell his story. So he’s stuck and he’s miserable. For the more his story is told, the more it drifts. He is utterly alienated from his name; it is no longer identical with him, but continues to bind. The cheerless woman across the way is praised as a saint, even though the roads in her heart were convoluted. The gray haired man at the vending machine was lionized as a warhero, then demonized as a warlord, and finally canonized as a necessary firebrand between two moments in history. He waits with aching heart for his statues to fall. And that is the curse of this room: since we live in the heads of those who remember us, we lose control of our lives and become who they want us to be.