I'm a terrible market-timer. And no more so than this year, when my futile attempts to play it safe seem straight out of a Rocky & Bullwinkle cartoon.

This spring, a change in my wife's 401(k) options dictated a total reallocation of our family portfolio.

Figuring that I was well-informed on index-related matters, the decision was made to stick nearly a third of our assets in cash. My reasoning seemed sound. Big government budget deficits and sure-to-rise commodity prices just didn't fundamentally add up to this rally proving to have lasting legs.

I forgot one important lesson, however. A few years ago, I made a tactical allocation by shifting more of my money into large-cap U.S. stock funds. Again, it seemed like a sure bet. Everyone agreed—large-caps were coming back after years of domination by small-caps.

And it happened. The only problem was that it took nearly two years for that trend to be realized in the market.

Now, I'm in much the same situation. It's not that my "tactical" moves haven't panned out. It's just that in the meantime, my portfolio returns are nearly 5.7 percentage points less than they would've been if I'd just stuck to my original plan.

One of the big reasons for that under-performance has been staying away from Treasury Inflation-Protected Securities. Dumb, dumb, dumb. As Paul Amery, our debonair and learned editor in London notes in today's feature (TIPS: Still A Bargain?), these ETFs have mounted a pretty impressive rebound this year.

The reasons why TIPS are back—and how they're doing compared with other types of fixed-income funds—make a timely and pointed lesson for would-be market timers like me.

The return of this asset class is a microcosm of what long-term investors are fighting. You've got to respect the diversification and price-hedging features TIPS provide. Still, it's easy to second-guess allocating a portion of your bond assets to funds like the iShares Barclays TIPS Fund (NYSEArca: TIP) or the SPDR Barclays Capital TIPS ETF (NYSEArca: IPE).

Even with so much debate about how big a factor inflation is these days, isn't the comeback of this category a moral victory for those of you who stuck to your long-term investment plan?

And as Paul points out, more ways to control risk and diversify your exposure to TIPS are on the way.

Hopefully, by that time, I'll wise up.