Personally, I've noticed that knowing and internalizing my hourly rate has decreased my enjoyment of life. When you contemplate the opportunity cost of even an hour with friends (>$100) it's hard to have much fun. Has anyone encountered research on this topic?
Also, a lot of people recognize that time is money, but rarely do they think that money is time. They never use their money to buy back time. Instead they use it to make more money. And now they have to spend more time protecting, managing and investing that money because if they don't, they'll feel bad about the opportunity cost of their money sitting in the bank and being eroded by inflation.
And enough people know how to earn money, but most people don't know how to spend it. When I say spend, I don't mean waste or reinvest. Consider: if you give someone X dollars, he will start by eating better food; give him 2X and he'll dress better; 3X and he'll buy a better car; 10X, a better house. This is usually where people's imagination start to fail them. 20x? Er... buy an even better car and a better house. 50x? Buy two cars and two houses. 100X? Buy a yatch. 200X? Buy a private jet.
Notice that after the lower levels of Marslow's hierarchy have been satisfied, people just don't know what to spend their money on. All they can think of is buying bigger and bigger versions of what they already have. You can't eat away a $100 million no matter how much expensive food you eat. You can't live in all the rooms of a 50-room mansion. All you can do is use your money to make more money or waste it. Not many think of spending it to buy back your time -- spend it doing something you like.
Thus, I use money to buy time which I use to earn money. (For example, paying for my laundry to be done so that I have more time to work.)
Obviously I still need to learn that increasing a random number in a bank balance doesn't actually affect my life at all.
It's also pretty common to not just buy tangible objects directly for yourself, but to buy the sort of community you want to live in. Endowing museums, universities and hospitals, sponsoring the artists and politicians that suit your tastes (and not just your business interests), etc.
I actually haven't found this even when working about 80 hours a week (~60 externally billable). The key is splitting it between 3 things: 1 primary employer; smaller contracts; building my own startup. The variation in work definitely keeps things interesting and productive.
As software engineers, we're paid enough to be able to do 4 or even 3 day weeks and chill out/hack for fun the rest of the time. When I escape my PhD (if I don't do a 24/7 startup) I'll be seeing how few hours I can work and still pay the bills.