It's just a pithy quote that is obviously false and yet very difficult to unlearn. People with different values can be equally happy. There are tons of objectively crazy people who are happy, and even a few who are rich. There lots of miserable people with "perfect lives". There are many approaches to learning something. There are many ways to contribute to a successful team. There are lots of good programming languages, and lots of different ways to solve problems.
I'm not suggesting that there is no such thing as happiness or that wrong can't be distinguished from right, I'm just pointing out that you'll probably go through life being very judgmental and probably unhappy if you really believe Tolstoy's quip.
