Tangentially: I think a lot of people forget/under-estimate how the industries behind their job are a factor when "diversifying" against risk.

In other words, a programmer should invest a bit more away from software than average, a realtor should invest a bit more away from properties than average, etc.

If you have your job, you can weather a stock-downturn, and if investments are solid, you can weather a period of unemployment, but if both go bad at once it's exponentially worse.