Expect the unexpected

I had planned to start re-reading The Motley Fool Investment Guide Sunday, both to brush up on its lessons and to share some on the blog.
I tossed my paperback copy onto the passenger's seat of my Hyundai when I set out on some errands. I figured I'd stop and grab a park bench sometime, and enjoy the afternoon sunshine with my book for a while.
I never made it to that park bench.
Instead, I opted to park the car and venture out for a long bike ride.
Well, that was cut short by an unexpected thunderstorm. It struck about 45 minutes into my ride. The winds kicked up. The lightning grew closer by the minute.  And as I raced up the last mile toward my house, the sky opened. It was quite the downpour.
I made it safely home, with a soaked shirt, but none the worse for wear.
Relieved, I stepped inside my house and listened to the rain rumble on the roof for a bit.
Then I realized I'd left my sunroof open.
Wide open.
It was sunny, after all, when I set out. People were strolling around, walking dogs, sitting along the Susquehanna's grassy riverbanks, just minutes before the storm hit. 
I guess it wouldn't have hurt to take a look at the weather forecast.
Now, The Motley Fool Investment Guide sits on a shelf, swollen like a sponge as it dries out.
The re-read will have to wait.
There may be an investing and money-management lesson in here somewhere, though.
Expect the unexpected.
Even when the market is looking bright and sunny and calm, storm clouds might not be that far off, and they can roll in very quickly.
It never hurts to take extra precaution, to pause and weigh your risk before making that next investment decision.
Because a seemingly innocuous decision, if not well-thought out, may leave you more vulnerable than you first thought.