$500k cash buys you a very nice triplex or quad in many parts of the US. Live in one unit, take income off the other two. No mortgage, positive cash flow. If you live frugally (used car, etc) you could afford to basically do what you want, work part-time, travel a lot, and enjoy the shit out of life.
Interestingly, you could also pick up a duplex or triplex for $500k in the less nice parts of San Diego County and do the same thing. Or 3 condos, which would amount to similar/better cash flow.