This is a good companion piece to another recent HN post:

http://news.ycombinator.com/item?id=3991122

I've found two axioms to hold true:

1) Don't compare your life to anyone's. Just don't. Comparing any two lives is fundamentally apples to oranges, because each life is its own thing.

2) Once you've got the bottom tier of Maslow's Hierarchy of Needs covered well enough where you can feel assured that it'll stay covered, money doesn't buy much happiness.