That, perhaps, is a lesson not yet learned at Southwest Airlines .

FORBES: Southwest Going Nowhere

He learned a valuable lesson about not just plunging into the market and buying four flashy, obvious stocks because you happen to play stupid videogames on a PC and have a vague, adolescent familiarity with the technology sector.

WSJ: Joe Queenan on the Son Who Bought Apple Stock | Moving Targets

Almost everyone is a veteran of Iraq and learned the tough lesson there about not declaring victory too soon.

CNN: Behind the scenes: Dreams of a power wash

It was a hard lesson learned, but here it is: Knowledge is not power.

FORBES: Knowledge Is Power? Those Days are Long Gone

Pryce said he had been under the impression he would not need a visa and said he had "learned a lesson".

BBC: Pryce visa woe a blow to Calzaghe

If there is a lesson to be learned from years of award season coverage, it is to not place too much stock in the Golden Globes.

FORBES: Golden Globes: The Good, Bad And Head-Scratching

It is a lesson that Mr. Rumsfeld and the military have already learned, but which the White House has not.

CENTERFORSECURITYPOLICY: Time for the Bush military build-up

I've learned a hard and difficult lesson considering the childhood environment that I was brought up in - not to discriminate against any plant or creature.

BBC: Norfolk - Chris Skinner's wildlife haven

It is unfortunate that Coy's school has not learned the lesson that so many other aspects of our culture have already acknowledged, that a person's gender is more complicated than a body part or a chromosome.

CNN: Gender identity not just body parts