There are so many examples I don't even know where to start. Disease eradication (through education, sanitation improvement, suppressing disease vectors, vaccination, etc), then there's poverty reduction, the way piracy was eradicated in the 19th Century, the way ozone depletion was tackled. There are endless examples.
Anyway, what are you actually saying other than taking a cheap shot?
An example of such a time, from various available such historical "sometimes"?