Whether a novice or a pro, we all may mistakes investing.

Sadly, for many of us, 2008 proved to be a year rich with bad options and negative results -- or, as I prefer to call them, learning opportunities.

Here's a review of some of the most painful learning opportunities in 2008:

#1 Going long the specialty retailers: If you made a bet on the specialty retailers leading up to the first $600 taxpayer rebate stimulus package, you got hammered.

#2 Betting on the China bull: Several ETFs that gave investors indexed exposure to Chinese stocks saw their values get hit for as much as 70%.

#3 Buying non-durables: Seems the kitchen and bathroom stocks didn't work this time around.

#4 Buying financials: Buying the financials while the Fed was aggressively cutting interest rates was supposed to be a no-brainer.

#5 Betting on peak oil: Crude is now trading around $40 -- down $107 per barrel in less than six months. Unbelievable!

Existing oil field output is declining about 4.5% annually, but new fields are making up for that production decline, a study by Cambridge Energy Research Associates concludes, The Wall Street Journal reported Thursday. (Subscription required.)

The annual decline from existing fields is about 4 million barrels per day -- about the amount oil No. 4 oil producer Iran produces per day -- with new fields offsetting the loses. The study is based on data from 811 fields, The Journal reported.

Depletion rates are one measure that oil sector analysts use to gauge current productivity, proven reserves that can be extracted, and probable future production output.

The measure also provides evidence for the ongoing debate in oil circles regarding the ultimate size of oil supplies -- with exploration bulls arguing that oil is decades away from a production top, and others, peak oil theorists, arguing that global oil production is likely to peak in the decade ahead, if not sooner. The debate is complicated by the fact that reliable production data on field-by-field production is not available from several key oil-producing nations, including Saudi Arabia, Iran, Russia, and Venezuela.

Insights summarizes an idea or business official making financial news, and emphasizes the impact on the typical investor.

Oil industry expert T. Boone Pickens has made news again, and also generated some chatter in Wall Street circles, but this time not for an oil price prediction.

Earlier, Pickens predicted that crude oil, which Tuesday traded around $85 per barrel, would hit $100 -- perhaps as early as Q4 2007.

This time Pickens made headlines by stating to Bloomberg News that global oil production has already peaked at 85 million barrels per day. In other words, "peak oil" has already arrived. Pickens, chairman of BP Capital LLC, spoke at a conference sponsored by the Association for the Study of Peak Oil & Gas, a non-profit research group.

This week's U.S. News & World Report, (August 13) features a series of articles collectively entitled "1957 -- A Year That Changed America Culturally, Scientifically, and Politically."

In the issue the magazine "takes a look at this seminal year -- one that planted the roots for a new America." Among the reports included:

• "Eisenhower Confronts a Political and Moral Crisis in Little Rock"
• "Sen. Strom Thurmond Sets a Filibuster Record to Hold Off Integration"
• "With Launch of Sputnik, the Soviets Open a New Frontier and Ignite the Space Race"
• "John Glenn Orbits the Earth, Setting Another Record"
• "The Dodgers Move to California, and the World Follows"
• "From the Wreckage of World War II Came a Vision for a Unified Europe"
• "The Bloody Battle of Algiers Demonstrated a Terrorist Playbook"
• "Ghana's Independence Set Off a Chain of Freedom in Africa"
• "The Edsel Went From Wundercar to Laughingstock"
• "The Laser Beam Revolutionized Medicine and Industry"