So, in the example above, assuming that you and your spouse cannot agree to a different result, the court is going to order the result laid out above. If you're that teacher, let's say, age 56, the court can order you to start paying your former spouse from your pocket because, even though you haven't retired, you could have, and so, your former spouse is entitled to start collecting. A Premarital Agreement can clear the tracks for that separate property train. You and your spouse can make almost any agreement you want in order to keep that tunnel-bound train in tact. But, the time to do it is before the train leaves the station.
Premarital Agreements vary from couple to couple.
Some people just want to inventory their separate property before they get married so that if they do get divorced, there'll be no question about whose stuff was whose. Other people want somewhat more elaborate arrangements, e.g., if I use separate property for community purposes, I get a return on my money. Some people want to keep their businesses safe from the other person. Others are willing to set up a community bank account with the proviso that only the money in that account is to be community property. Everything else is separate.