Yes, that is a serious question!
Average life expectancy has roughly doubled in the last 150 years. Whereas life expectancy at birth 150 years ago was around 35-40 years it is now around 80 years. (See Why are you not dead yet? which is an interesting read.) Well OK they’re figures for the US, but the UK and rest of the developed world isn’t much different. According to Wikipedia medieval life expectancy in the UK was 30 years, and was still only 31 years in the early 20th century. Indeed (according to World Bank data, via Google Public Data) UK life expectancy has risen 10 years in the last 50!

Forget airplanes, cars, nuclear weapons and the internet. This increase in life expectancy is probably the most important difference between our modern world and life 150 years ago.
Before the advent of modern medicine — and a lot of that has happened since World War 2 — infant and child mortality was incredibly high. And many of those who survived into adulthood were killed by accidents or disease which would be easily vanquished today. Just as an example, one of Noreen’s relatives about 100 years ago died in his mid-30s of erysipelas (St Anthony’s Fire), a bacterial skin infection which today would be quickly cured by antibiotics.
Remember that just because your direct ancestors lived into their 50s, 60s or even 80s, there were many children who died before puberty and hence are no-one’s direct ancestors. In the 19th century families of 10 or 12 children, with only one or two reaching adulthood, are not uncommon. And it was a lucky family which didn’t lose a single child even well into the 20th century.
In fact there is a good chance that you — yes, you reading this! — are already on your second or third life. And that is almost certainly down to either modern medicine or modern safety (think things like seat belts and air-bags).
In my late 20s I had appendicitis. It grumbled for a year or more until the medics decided what it was and removed the offending organ before it blew up. Without that medical intervention I would likely have died of peritonitis within a year or two. Noreen has similar stories — blood poisoning from an infected toe injury; a shattered left elbow (which would have been at least disabling). And we have both been extremely lucky with our health!
We all forget how common such diseases and injuries are and how much we have come to take for granted that they can be fixed. We also forget all those illnesses (smallpox, polio, whooping cough (aka. pertussis), measles) which we never or seldom see because of vaccination.
So tell me, please, why are you not dead yet? Without modern medicine what would have killed you? I’m curious to know.