When I was young, there was fog. I remember going into school in the morning when the fog was so thick that I couldn't even see the athletic fields from the front of the school. But after that I went years without seeing any fog. I wondered if there hadn't been any fog during my adult life, or if it was a matter of fog being limited to the early morning, and my not getting up early enough any more.
I did see some fog one morning a few weeks ago. And there has been a lot of fog in the weather forecast recently, including predictions of "zero visibility" for some areas. I have never been in conditions of zero visibility, but I would like to be. I imagine, though, that zero visibility can be simulated by standing very close to a wall, and staring directly at the wall.
I also like to imagine fog so deep and thick and enduring that the government announces that the only way to deal with it is stay inside and sleep for days on end.