Lucky you! I was 20, brilliant and totally lost. Now I'm 36...
Don't feel guilty if you don't know what you want to do with your life. The most interesting people I know didn't know at 22 what they wanted to do with their lives. Some of the most interesting 40-year-olds I know still don't.
HOW soon hath time, the subtle thief of youth,
Stolen on his wing my three and twentieth year!
My hasting days fly on with full career,
But my late spring no bud or blossom sheweth.
Perhaps my semblance might deceive the truth,
That I to manhood am arrived so near,
And inward ripeness doth much less appear
That some more timely happy spirits indueth.
Yet be it less or more, or soon or slow,
It shall be still in strictest measure even
To that same lot however mean or high,
Toward which time leads me and the will of heaven.
All is, if I have grace to use it so,
As ever in my great taskmaster's eye.http://www.infoplease.com/ipa/A0005140.html
So the average 20 year old in 1850 could expect to live an additional 40 years, to roughly age 60. The curve started flattening after WW1 and continued doing so until around the 70s and 80s.
Here's hoping for the hockey stick.
I suspect there were significant differences in life expectancy between the 17th century and 1850.
Henry David Thoreau