Let's say you have $100,000,000 dropped in your lap. You now never have to worry about needing money ever again, which in our current society means you don't need to worry about a LOT of problems.

So it's natural that most people want to preserve that security, the best way to do that would be to invest the money in a way that it grows equal to, or faster than you will spend it.

You can just get it all in cash and stuff it under your floorboards, but there's a non zero chance that the money will be physically destroyed or stolen from a disaster.

You can stick it in a bank, but you have very little protection for the bulk of that money from the government insurance.

So the smartest thing to do is to spread that money out to investments that will grow that money in a diverse way to protect your newfound security.

Once that is set up, you create a will (or trust) to handle the money when you are dead. Who gets to benefit from your windfall once you're gone?

Then you have complete freedom to live your life how you want to.