Understanding your cash flow is essential for financial stability.
Looking back, there was one month I ended up being late on a credit card payment because I didn't have enough money left over after paying rent, all thanks to a sporadic big purchase. Talk about a wake-up call.
This late payment taught me the importance of understanding my spending limits each month, and of course, the essential need for budgeting. If there was a big-ticket item I needed or wanted, I would need to plan for this purchase, while being conscious of my cash flow to avoid sliding down the slippery slope of credit card debt.