No Spend Challenge Update

I've always wanted to do a no spend challenge but was always afraid to bite the bullet and do it. My friends are asking me what a no spend challenge is, apparently not everyone is a money/budgeting nerd like I am. I explained it like this; you set a time limit like a week, month, whatever, I chose 10 days. During the time you set you cannot spend any money beyond basic necessities, you know like groceries, gas, bills or things you have previously committed to. I started my challenge on Tuesday, this means I completed day #3 without spending anything. Has anyone else taken a similar challenge and were you successful?