This is just my thoughts spilling out but my husband just said to me "I've told your dad I'll be round at the back of 11" and i'm like so is that 5 past 11 or 5 to 12? And he laughed because he has definitely explained it to me before and I just can't wrap my head around it.
The back of something, to me, sounds like it would be the end. So I imagine it to be closer to 12.
I know I am wrong. But the saying is bullshit.
There. I said it.