There are no stupid questions: only stupid answers. Here are some which could be mistaken for stupid questions.
"Where is Leeds Castle?" Hint: nowhere near the big northern city called Leeds.
"What's in my hamburger?" Hint: not ham.
"What date was Jesus born?" Hint: probably not 25th December, according to many scholars. That's merely the date we celebrate it.
if he would be ok to get money out of a cashpoint in France because his bank account was only in English money! Not a stupid question at all. I'd hesitate to do this, because it might incur much higher handling fees than accessing the money another way.
Are God’s parents Mr and Mrs Big-Bang? Many Mumsnetters would answer that with "God doesn't exist, who indoctrinated you? God help them!"
I swim in the river through the year. In the depths of winter, we regularly get ‘is it cold?’ In the height of summer, is it hot? Like water from the hot tap, with steam coming off it? Genuine question.
Are you a nurse? You might have been an actor for Casualty. (Apparently it did happen, that actors were mistaken for nurses!)
What time is midnight mass? Not midnight at my church either. Although I remember a time at my parents' church when it was supposed to start at midnight, and in the silence, lots of watches went "beep beep" (remember the watches which beeped on the hour?), and still nothing happened for several minutes. Jesus was late that year.
Half way through the film "Ghost" the woman next to me loudly asked her friend if Patrick Swayze’s character was dead. I've only seen it once (and thought it was really dull), but isn't the case that Patrick Swayze's character didn't even realise he was dead, until he saw his partner looking at his dead body?
Somebody asked her if she was having ivf because blind people can't have sex because they can't see where the other person is! You should have told her that some people like to be blindfolded while they have sex, that would have blown her mind. And as Ebenezer Blackadder observed: "how the ugly royal family managed to procreate, I've no idea. The bedchambers of Buckingham Palace must be copiously supplied with blindfolds."
Well I once asked my colleagues what time the 24h Tesco closed at 4pm. On a Sunday, at least. As a student one hot and sleepless night, I went to Asda at 2am just to see who went shopping at that time. It seems the answer was lots of cardboard boxes (the aisles were full of them), and a man with a baby.
What's the time (in a clock shop)? Lots of people might have said "ten to two" as a first answer.
Mind you, my mum has a habit of asking "is it raining?", because doing so is simpler than looking outside.