In the Upper Paleolithic, life expectancy at birth was 33 years, and by 15 years of age the total expectancy went up to 54 years.
In Classical Rome, life expectancy at birth was 20-30 years, and by 10 years of age the total expectancy went up to 45-47 years.
In Medieval Britain, life expectancy at birth was 30 years, and by 15 years of age the total expectancy went up to 64 years.
This looks kind of mixed to me. Certainly, as you point out, people weren't "dropping dead at 30". But dying around 45 or 55 is not what people nowadays would call a "fairly full adult life" either.
[1] http://en.wikipedia.org/wiki/Life_expectancy#Life_expectancy...
Certainly in a sociological sense, most people consider the years 60+ to be twilight years where you're not living life to the fullest - whether it's true or not, that's the perception.
Hunter gatherers were lucky to live past 30...
Not true. If you made it past 5-10 years, you were likely to live a fairly full adult life. Infant mortality was very high, but it wasn't like most people dropped dead before 30 if they survived early childhood.