Back then it was common for someone to work for only one company, starting at age 18 and retiring at 65. You took your pension and gold watch and went home to sit on the porch in a rocking chair. Ah, the good 'ole days!

But those times are long gone and the magical retirement age of 65 isn't so magical anymore. The workforce is getting more gray hair as Americans continue working into their late 60's and on into their 70's.

Social Security hasn't considered 65 as full retirement age for a long time. The last workers who received full Social Security benefits at that age were born in 1937. For people born in 1938 and beyond, full retirement age has been increasing by 2 months per year up to those born in 1960 and after, when full retirement age caps at 67.

According to the Bureau of Labor Statistics, in 2016, almost 27% of Americans between 65 and 74 were still working. That's projected to exceed 30% by 2026. And the number of people 75 and older who continue to work has gone from 6.4% in 2006 to 8.4% in 2016, projected to hit almost 11% by 2026.