By now, the cold fear of the financial crisis has receded, even if its effects linger. The recession has been over, technically anyway, for nearly four years.
Unemployment, if still high, is falling. The economy, while growing slowly, at least isn't shrinking. Inflation is still low.
The Dow record doesn't necessarily mean that investors believe the economy is fully healed. Rather, they're confident that the Fed is willing to keep pumping money into it. They've learned to ignore budget fights in Washington.
It's impossible to predict how long the bull run could continue. But so far, there aren't all the tell-tale signs that it's about to run out.