(pots by Gary Rith, pond scum on clay by Mother Nature)
Learning pottery is fun, and instructors enjoy telling you strange stories about pottery and nature and whatnot. Basically, as long as it is not dried out, old clay is better clay. Little microbes, algae, pond scum basically, grow over the course of months in and on clay, and that improves elasticity. This clay is about 8 months old, and look at that lovely black muck on it!
OK, also messing about with mug shapes.