The 10 million (in whatever your currency is) is in a bank account only you have access to. You can spend as much, or as little as you want, but if anyone even gets a thought that you are a millionaire, you lose it all. This includes spouse, children, parents etc. Once the 6 months is over, you can tell whoever you want.
The people at the bank wouldn't know who you are, so wouldn't be classed as knowing. Buying expensive things though might draw attention. Do you think you could last the 6 months?