Those numbers work fine with what I said, they're fairly full adult lives. Life expectency has been rising over the past few decades with improvements to medical care, but only 50 years ago in the US, it was 70 years. If that's 'full', then the numbers above are 'fairly full', I think. Rome might be a touch short, but it's still much longer than the idea most people drop dead by 30.
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.
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...