My father did everything right. Saved for college for his kids, retirement, 401k, etc. He was serious about saving and only paying for things with cash to avoid the credit card debt.
You can do everything 100% correct and still have life kick you in the butt. What will happen to your nest egg if you get a serious illness, job loss or disability? My father was diagnosed with a medical condition that forced him onto short term disability and also into his retirement money. He has bounced back quite well, but statistics show that most folks do not get so lucky.
This article has great facts about reitirement and avoiding a financial nightmare!