Excellent article. I think that one of the things that you've mentioned several times (and written about in your books) that has really resonated with me is the ability to have a Plan B, but invest for your Plan A. I do plan for swings and downturns, and I have a reasonable plan that "should" be OK but I can't invest for every last disaster known to mankind. However, if something were to happen that would prevent my best plan from working for me, then I move on to Plan B. There are just too many variables. I believe the key is just being flexible.