The truest measure of wealth is the degree to which working becomes a choice. It's a continuum - a little wealth gives you short-term freedom like choosing to start a business, whereas $10m+ gives you the option of doing whatever you like for the rest of your life without worrying about an income.

I suspect most people have things they like to do if they suddenly came into a large fortune, but continuing at their day job is rarely one of them. Actually, with people who win the lottery you often see the opposite - they don't need to work, but they feel pressured to do something and often end up losing spectacular amounts of money in foolish business ventures.