I would probably treat myself to a new car, but beyond that, I'd carefully invest it, but not change much of anything else. I'd still work at my job because I like what I do, and I'd decide whether or not to pay off the balance of my house or just speed up payments - but not much else beyond that. It would just give me more security for retirement down the road, but not something that would cause me to do anything like buy a big house I don't need or quit my job.