In terms of cultural knowledge, it does seem like certain things were taken for granted by previous generations and not handed down in ways that younger generations can manage.

You are simply ignorant of how large duvets can get (taller than 99th percentile).

Maybe that is part of my ignorance. I am quite tall, probably in the 97%

King size duvet is 245x210 cm and weights few kilos. No way you can manhandle this.