This reminds me of a lesson learned in my life...
When I was a teenager, (16-17 years old) I bussed tables for two different restaurants for two summers to save up money to move out of my mom's house.
I probably averaged about $100 a day in tips, usually in $1's.
I had a big old heavy oak desk with a locking drawer I would count off $50 rolls, rubberband them and lock them in the drawer until it was time to take them to the bank.
After doing this for months, I was often surprised to find that it just didn't seem like I was making as much money as I thought I was when the time to go to the bank and make a deposit came around. (Usually about every two weeks when I got my measley minimum wage paycheck.) I never had any reason to think that someone had stolen my key and compromised my saving spot. This desk had 1" walls of solid wood.
When the time came to move after graduating High School, I gathered up all my friends to help me move, and as we pulled the big oak desk away from the wall, I discovered that my older brother had "dug" a hole, ala
Escape from Alcatraz, in the back of the thin wooden panel of the heavy oak desk just big enough to fit his hand into the drawer and occasionally snatch out a roll of bills, but never too much to make me really notice.
From that day on, I've always kept a tally sheet in with my petty cash even when I lived alone for 10 years.
