Many people use two shower curtains in their bathrooms: one inside the tub and an outer one.
The tennis-themed shower curtain contains sporting instructions that would help the budding Federers and Mauresmos hone their lobs and volleys even while in the bath.
David Schmidt got the 2001 Nobel Prize in Physics for explaining partly why shower curtains blow inwards.
Shower curtains should be replaced every few years for hygienic reasons.