Who knows what goes on in a family? I learned this as a student.
'You can spend years with a patient and still they'll surprise you,' Wesley told me after we'd shaken hands for the first time, his fingers yellow with nicotine.
'How so?' I asked.
He settled himself behind his desk, clawed his hair back. 'You can hear someone's secrets and their fears and their wants, but remember that these exist alongside other people's secrets and fears, people living in the same rooms. You've heard that line about all happy families being the same?'
'War and Peace,' I said.
'Anna Karenina, but that's not the point. The point is, it's untrue. No family, happy or unhappy, is quite like any other...'
The Woman in the Window by A J Finn, page 98
The narrator is a child psychologist; Wesley is her tutor.