I see it as one of two things.
The age of the internet – If the internet doesn’t continue. If something makes it unsustainable or societal collapse just leads to the loss of the infrastructure necessary for it (not an insane possibility considering how much we’ve lost with collapsing civilizations in the past)
BNH – As in, Before Nuclear Holocaust. If we should all collectively lose our senses to the point that we wipe ourselves for the most part off the earth, the few survivors picking through the rubble and dodging radiation clouds will likely refer to our time as the before, as humanity will have a new defining hurtle by which to measure time.