"The importance and scarcity of time. Your "you time" gets seriously reduced as you get older and your other responsibilities mount up. I used to think that spending half an hour cleaning 3 times a week was the worst thing ever. Now I spend about an hour cleaning pretty much every day. Between work, maintaining a house, and raising kids, the amount of you time gets reduced to.minutes a day. Anything else you want to do means sacrificing sleep.

The other thing is how true "time=money" actually is. Simply existing and breathing costs money. Food, rent, bills, transport cost money. Often the difference between happiness and unhappiness for me was comfortably making it to my next paycheck."