"No money" challenges

I last year I made $14000 AUD ($10000 USD), lived relatively comfortably and had a few short holidays. One of the ways I learnt how to be frugal was from doing 'no money' challenges. Basically you see how long you can go without spending a cent. When you break your streak and buy something, write down how long you lasted and try to beat it next time. I had a few variations of the rules each time, like exceptions for transport costs to get to work, starting with a few kilos of rice and some oil, or starting with no food at all. I usually last between 1 and 9 days as its quite difficult to do in the city, but each time i did a challenge it became easier.

Anyway i think it would be amazing if someone would try this. Let me know what you think? :)