BelArgUSA:
As stated above, far fewer of the young 'know-it-alls' will want or be able to afford to retire when they hit age 60 than assume such right now.
Among many other future problems, many will be ordering their required drug prescriptions from Canada in order to afford to keep their First Class medical licenses-or keep their future wife alive with a medical condition which won't be diagnosed for another 20 years. They might think: "What wife? What kids? I'm not married yet!" That's the point.
Mine has type 1 diabetes (diagnosed when she was about 40...) and does a very good job with it.
What will YOUR extra costs be? When you retire, your various benefits are not so good as they were. And remember, the US no longer, or barely qualifies as an "advanced industrial nation" by various measurements.
They can not know for many years what will happen in their lives. Just wait until someone like Hillary really screws up our medical system (and just on the Federal level...not including the other confusing jurisdictions...heard of Katrina's aftermath?).