[fancyketchup]

The page I cited actually breaks down lifetime earnings by age (a.k.a. "annual income"). It's true that non-college graduates get an earlier start on savings, but the overall trend is that their annual income starts to decline as they get closer to retirement age (they peak in their mid to late 40's).

You have to assume totally unrealistic investment gains in the first four years to make up for the $500k less total income.