For more context, 25 liters is only enough water to take either a three-minute long shower or flush your toilet four times, and either way, that's all your water used up for the entire day.
The very first known flushing toilet was invented in England in 1596, but it remained a royal luxury, and things didn't change all that much in the butt wiping department for a long time.
This could mean getting a fairly decent apartment, or living in a place heated by an open fire that does not have a flushing toilet or reliable electricity.