Time Warner’s (NYSE:TWX) long-overdue decision to spin off beleaguered AOL reminded me of a lot of other long-standing economic delusions that are now coming unraveled. After a long, drawn-out vacation from harsh reality, we've entered a new landscape, in which AOL's spinoff -- perhaps a final, official admission that one of the major mergers of the dot-com era failed -- seems particularly poignant.

We may be poised to shed a lot of enduring economic illusions. But I'm still not sure whether we'll learn any lessons in the process.

Delusion No. 1: This time it's different
The Time Warner/AOL hookup came to epitomize the dot-com bubble, when speculative "investors" snapped up Internet stocks with wild abandon. Too many people figured things were "different this time," forgetting important considerations like, oh, whether these companies were actually profitable.

There were important survivors, including Amazon.com (NASDAQ:AMZN) and Yahoo! (NASDAQ:YHOO). But Yahoo!'s recent struggles (and AOL's long journey downhill) also teach us that competition is a constant risk, and that we always need to monitor whether our companies are losing their advantage. Google's (NASDAQ:GOOG) birth changed the competitive landscape.

Sirius XM (NASDAQ:SIRI) is another stark reminder of hard-learned investing lessons. Satellite radio was an important disruptive influence in the media landscape, but its debt-heavy strategy, and encroaching competitive innovations from entities such as Apple (NASDAQ:AAPL) and Internet radio, meant this company never became a profitable enterprise, despite all its promise. 

Delusion No. 2: No, really, this time it really is different
I remember watching as folks who had embraced the dot-com bubble with little thought of pondering financial statements turned to real estate after the dot-com bubble burst. Those who had said "The only way to get rich is through Internet stocks" swiftly switched to, "The only way to get rich is through real estate." Talk about traders -- they traded one speculative delusion for another.

They weren't entirely at fault, though. The Federal Reserve's zeal to boost the sagging economy after the dot-com bubble burst helped set the stage for a monumental asset bubble that artificially inflated the economy, leading to the major pain we’re feeling now. Speculative mindsets and flawed conventional wisdom that "housing prices can never go down" (even if the rate at which they had been going up was unprecedented) added fuel to the fire. Exotic, borderline immoral mortgages got avidly snapped up by unwise customers. Now, even prime loans are in danger, because too many people simply took on too much house.

The delusion felt good, though, didn't it? And homeowners who were feeling flush -- and using their homes as ATMs -- helped overexpand many parts of our economy in a massive ripple effect of delusion. Many retailers overexpanded, swollen by consumers' unsustainable and debt-fueled spending. Starbucks' (NASDAQ:SBUX) current troubles are testament to this, and the woes afflicting luxury retailers like Nordstrom and Saks reflect consumers' return to reason (and savings).

Shedding delusion and learning from the past
The boom/bust mentality is not exactly new. History shows that human psychology has put us in this place over and over again, even with commodities as seemingly simple as tulips. Far too many economic disasters have sprung from the words, "Everybody's doing it."

Consumers' new frugality implies that we've learned at least a few lessons -- possibly the hard way -- but troubling signs remain. The recent rally smacks of speculation to me; many stocks have soared, despite major warning signs such as massive debt and declining revenue. General Motors shares jumped when it was already clear that GM was bankrupt  -- game over for shareholders -- which told me that some people are still willing to gamble without thought or reason.

Last but not least, the Federal Reserve's actions, which threaten serious inflation in the future; the emphasis on stimulating lending, when it's clear many people and companies are already overly indebted; and our government's continued massive deficit spending all bother me. I fear we may once again trade one delusion for another, instead of letting the sick economy correct itself, which would much better pave the way for real growth in the future.

Tough times provide valuable lessons for those willing to learn from them. I'm hoping that we can all return to reason, putting the brakes on speculative thinking, and remembering that if something seems too good to be true, it probably is. We all need to be accountable for and aware of the risks we take. Can we shed delusions in investing, and in our economy? I'm hoping so. Otherwise, we're heading for a fall -- just like last time.

More Foolishness: