I wonder if astronauts can wish upon a star? Maybe they have special rules about wishing like “You can’t make a wish on Uranus because that belongs to the Russians” or “No wishing for a parallel universe.” In space, you have to be careful what you wish for. If you get that pony you’ve been wanting, where are you going to put it? And everytime it pees, do you have to drink it? Um, no thank you. I’ll have a diet coke please.

Lab animals on the [International Space Station] breath and urinate, too, and we plan to reclaim their waste products along with the crew’s.
Quotation from Layne Carter, Marshall Space Flight Center

Water on the Space Station (science.nasa.gov) Rationing and recycling will be an essential part of life on the International Space Station.

When Paris has to pee, Paris has to pee!
Quotation from Paris Hilton

The only rule is don’t be boring and dress cute wherever you go. Life is too short to blend in.
Another quotation from Paris Hilton