The expectation of retirement is part of the American dream. But the age at which we actually reach that expectation has been creeping up lately.

A new Gallup poll finds the average expected retirement age is now up to 67, up a lot from 1996, when people expected to retire at age 60. Rider University finance expert Maury Randall says to make the perception a reality these days, they will need a larger amount of funding than people years ago, who did not expect to live so long. The same poll found that more than half of the people who aren't yet retired don't think they'll have enough money to live comfortably in retirement.

But with advances in the health sciences, life expectancy is now at 78. That door swings both ways. We can retire later in life, but a longer life expectancy means the so-called, "golden years" may be extended.

Still, younger workers are more optimistic than their older peers.

Gallup's annual Economy and Personal Finance survey, which was conducted in mid-April, found that people who are currently under age 40 expect to retire at age 65. Those who are 40 and over, and not yet retired, expect to retire at 68.