It's not ridiculous at all.
We teach children not to talk to strangers.
We teach girls to be careful around males of any age or to be wary of anyone who wants to engage them in conversation & ask to e.g. show them a puppy/sweets etc..
We teach then not to stop to talk to strangers in the street asking for directions/the time etc.. & to disbelieve strangers who tell them 'I know your mummy/daddy/granny/teacher etc..)
We teach them not to be in isolated places with strange males in particular but also to be wary of being in isolated spaces with strange women.
It's why so many adult people step over or ignore collapsed people or people exhibiting signs of extreme distress in the street.
They are taught not to get involved because it might not be safe.
They wouldn't ignore someone they knew even vaguely.
People are distantly polite, they usually smile if they catch your eye, they may indicate that a cubicle is available if they are waiting for someone else but not using the toilet themselves in case someone thinks they are in the queue, but they don't strike up friendships or perform social stroking in the loo unless they are drunk or with people they already know.
Women don't go to the toilet to have social interactions with strangers.
They go to use the toilets.
Women grow up being taught the world can be an unsafe space.
Don't wear that skirt, don't leave your drink unattended, don't go out alone, don't walk down that dark lane, don't take that shortcut etc...
It's not because the skirt, drink, lane etc... are dangerous.
It's because MEN might use those things as excuses or opportunities to harm them.