Try to keep a healthy dose of skepticism -- but these two companies could be on the brink of shocking investors.Long-term investing requires optimism. This is why investing in turnaround opportunities is intrinsically dangerous. The danger to investors is the failure to properly assess the risks because they look at the opportunity through rose-colored glasses. Their optimism emphasizes the good possibilities instead of the bad ones and makes it harder to develop a balanced assessment.Businesses sometimes p ...