Back in the day, when I was a poor college student, most of my income came in cash; cash in small bills. I was a waitress. I learned quickly that I could not be trusted to carry around my nightly wages. It was too easy to spend a few dollars here and there, and find myself flat broke until my next shift.
I also quickly came up with a solution to this problem. After my shift I would take a seat in one of the bar stools, and count my money into two piles. One pile was for the bills, and the other for the fun stuff. Immediately after leaving the restaurant, I would deposit the bill money at the ATM across the street. I didn't have the best money management skills, but with this system, I rarely found myself short come rent time.
Those were the days of ATM cards, not debit cards. The days when it was rare to find a grocery store, restaurant, or gas station that would accept anything but cash or a credit card. The days where ATM's were few and far between, not on every corner. Depositing my cash limited my spending. I had to stick to what was in my pocket.
Many years later, I now find I need to handle my money in just the opposite way. I do better when I have cash, especially when that cash is separated into spending categories. Now that virtually every business will accept my debit card for payment, it is too easy to whip out the plastic, and lose track of how much is spent. It is easy to come home with a wallet of receipts to enter into Quicken and only then realize that I've overspent my budget. You can't overspend your budget when you are only using cash.
The increased use and ease of debit cards has made me change how I handle money over the years. I find it interesting that my perspective has done a complete flip. I guess times change, and we change with them.