Five year ago, I had the advice from an entrepreneur that to get big things done one should have a life plan. I've been following one ever since.
On the goals side, it's made certain investments and of time and money into my career easier to plan (and stick to) - e.g. finishing two designations and a degree in the past four years. Similarly, my wife is planning to develop a career outside the corporate world that better reflects her talents (and the limitations that face a mid-career newcomer to Canada in the corporate world).
It also helps really deal with the full range of outcomes through exploring some simple scenarios. Recognizing some hazards, we've acted to mitigate unlikely but extremely deleterious events were to come to pass. It's in this light that this year we've made substantial changes to our investment strategies and also acquired life insurance for me as the sole earner.
For the long-term, we're weighing the options between retiring in Canada versus rural sub-tropical Japan (guess how that's going) and what it will mean for our plans.
We even find it helpful even for minutia such as ensuring that I arrange for vacation time, camp-site rentals, etc early enough in the year to actually get the dates we want.
I feel that this is important enough that I'd consider some sign of this kind of capacity for strategic thinking in one's personal life a strong plus in a job candidate and a must in a business partner.
(This was originally a post to a LinkedIn thread on having a personal strategic plan.)