Aside from Velcro, time is the most mysterious substance in the universe.
This is true; virtually all edible substances, and many automotive products, are now marketed as being low-fat or fat-free. Americans are obsessed with fat content.
Aside from velcro, time is the most mysterious substance in the universe. You can't see it or touch it, yet a plumber can charge you upwards of seventy-five dollars per hour for it, without necessarily fixing anything.