Once, in the mid to late 2000s, my high school English class was using some old textbooks that were fished out of some dusty closet. They had last been used apparently in the mid-80s. When I opened the book that was handed out to me, the pages were stuck together. I pried the pages apart to find a 1980s-era mustard packet that some cheeky teen from many years past had lovingly slammed shut into the to-be-time capsule of a textbook.