> Not sure what the hell I'd do if I won that, it's kind of a stupid amount of money
Well, in the Paris region, where a nice house (not the common 3-cupboards configuration with 20 cm of "garden" round the house) costs upwards of one million, any "I'm filthy rich" type of prize has to be over 10 millions...
So, get a nice house with a real garden, furnish it, stop working for a living and henceforth only do things you like to; Kind of early retirement, but without loss of purchasing power. Travel, visit the nice places of the world, Make sure your kids and your relatives' kids can study. Create a family foundation to keep your family and descendants safe when you're gone, and you will be fondly remembered through the ages.
Alternatively, buy a couple supercars and a kilo of coke, rent the presidential suite in the most expensive hotel, and spend your nights in some luxury casino, surrounded by the most desirable call girls/boys. When the week-end is over and the money spent, go back to your current life and live in memories of the couple days you were a millionaire.
There is unsurprisingly lots of stuff you can do with lots of money, although some are more sound than others. Your imagination is the only limit...