And most people do just that - spend and spend and assume that since they are balancing their checkbook every month, they are being fiscally responsible. They don't think about the more important things - like their overall wealth.
Once you think of things in terms of net worth, the idea of spending $400 on a new "smart phone" and another $100 a month to use it seems, well, sort of stupid, as do most consumer purchases. You will start to think long and hard about squandering money on shiny trinkets and beads - which may not last long in this world - at the expense of your overall Estate.
Get out of the cash-flow mindset and into a net worth mindset. It is the key to real, not apparent, wealth!