"Happy families are all ..." -Tolstoy's

Today in my friend's car was playing Tolstoy's Anna Karenina audio book.
The book began with following sentence
"Happy families are all alike; every unhappy family is unhappy in its own way"

In a society, people stick to same formula to be successfull and happy. So no wonder happy families look alike.
On the contrary, any off-formula life, may lead to very unique troubles.