I would be so screwed. This actually happened to me:
I always go to the same Walmart that's closest to my home. The Ladies Room is on the left and the Men's Room is on the right. Well now, I was in Summerville and needed to go to Walmart. Once in Walmart, I needed to go to the restroom. I go charging into the restroom on the left. WELLLLL, guess what. In the Summerville Walmart the Men's Room is on the left and the Ladies Room is on the RIGHT. I was so embarrassed. It should be against the law to change the location of the restrooms in two identical looking stores. I now LOOKED at the name on the door before charging into ANY restroom.
Funny...but at least you can still go potty if necessary even if it is the wrong room.
Personally, I think the cruelest restroom signs are the ones for pay toilets. My mom never seemed to have a dime on her when I needed to go when I was a kid. Thank God they did away with those for the most part (I guess they are still around just not as prevalent). At least I can't remember the last time I had to pay to use a toilet.