Around two months ago you woke up. This in itself isn't anything out of the ordinary, aside from two minor details. One, you couldn't remember anything, and two the world appears to have recently ended.
You wandered around dazed at first. You appeared to find yourself in a what could have once been a city, great rubble of gleaming metal, shards of glass and smashed displays, broken paving and upturned flagstone lay all around while nature crept in. Weeds had sprung up in the gaps that gave well to the ground underneath the ruins and vines were beginning to entwine what little still stood. Bits of broken technology you couldn't identify half buried in new grass. The place was quiet but that did not mean safe.
You were one of the lucky ones; your survival instincts kicked in, and you were able to get by, fending for yourself, or perhaps finding a couple of other people who you trusted enough to work together with. Trying to piece together what little civilisation you had left, it quickly became apparent from further discussions that you are not the only one; it seems nobody can remember anything before a similar point in time.
There was not time to dwell on these questions too much. our more immediate concern was surviving; finding water, gathering food, rebuilding shelters, and maybe finding other amenities to make life a little more comfortable for yourself. Some were not so fortunate. There were many died in the intervening period. By day, there would be attacks as people fought over resources, scrabbling over the remains and by night, people cried out and sleep never came easily as the night air chilled. Those left alive are those who could manage to get by. It's hard to say how many you number. It's hard to tell how many people you encounter when it's so easy to mistrust strangers.