I'm less than 50 and I remember how life was (Italy here). When I was little some children had polio and couldn't walk properly, I didn't know why at the time. Luckily they were the last ones and luckily I was vaccinated. However I had both measles and mumps, not a big deal but maybe only because I was little or because of proper treatment. I think every child at school had them sooner or later and all of them came back to school. We were the last ones not to be vaccinated against those diseases.

As an adult I got vaccinated against hepatitis, cholera, yellow fever, typhus, tetanus etc (I travel around the world on vacations). No consequences. Vaccination for me is an obvious choice. I can think that measles is easily survivable but I won't expose a child of mine to polio. Get all the vaccinations they offer you, it's a good investment.

However, if you don't live a problem you don't really appreciate it. Example: talking with people born in the mid 80s, it was impossible to convince them that there was a real concern about nuclear war at the time they were born (remember Reagan, Brezhnev, Andropov, the Star Wars shield?) Obviously nobody was going to fire missiles, they say. Go read the newspapers, watch the movies, etc I say. No way.