My city is in the middle of the worst drought in recorded history. My showers are typically under 2 minutes and I have to shower with a bucket to catch otherwise wasted water to use to flush the toilet. I also shut the water down when I am wet enough so I can scrub myself without having unneeded water flowing then start it back up to rinse.
Plus, water is damn expensive!
Who here really has the time to stand, think and waste in the shower?
I want you to know that individual water use is essentially negligible compared to industrial and farm use, neither of which tend to have any limits or restrictions, not even have any self-regulation.
I guess what I'm getting at is that the rich are the ones burning down the planet and any sacrifice you make in the meantime is meaningless. Take long, hot showers. As many as you want. Enjoy them. Because there will come a day soon where they'll be a luxury no longer offered, and it will not be your fault.