An hour and a half is exactly the same as half an hour
A childhood belief about general

others believed things like this
- I used to believe that all songs were exactly a half-hour long.— Brian
- I used to believe that your belly button was what held your top half to your bottom half...— Debelouwho
- I used to believe that a quarter after the hour was 25 minutes after the hour because 25 cents = a quarter.— Marni
- You had to wait an hour after eating ANYTHING, even one M&M, before swimming. Anon
- I was never able to get a good answere as to what hour of the day "evening" actually began— Tad
- I used to think that if you held a turd in for more than an hour it would give you bad breath— phil