My wife took tap dancing lessons once. Once.
As someone who once repaired trains for a living, a 300 ton freight car would run on 4 axles, a total of 8 plain bearings. Each 'journal bearing' was simply a piece of brass babbitt sitting on polished steel, with oil wicked out from a bath into the bearing via fibrous cloth. After 200 years, they were finally phased out for roller bearings but still, pretty amazing.
There you go, you all learned something new today!