When I was a child, I lived in walking distance of my elementary school. One time my mom had to work early so she couldn't be there to see me off to school. I was old enough to walk by myself at that point, but I relied on her to tell me when to go. Since she wasn't going to be there, she told me to leave at "quarter after 7" so I could be there on time.
I left at 7:25 because a quarter is 25, right?
I got in trouble for being late to school. Instructions unclear, Mom!