"Absinthe makes you crazy and criminal, provokes epilepsy and
tuberculosis, and has killed thousands of French people. It makes a
ferocious beast of man, a martyr of woman, and a degenerate of the
infant, it disorganizes and ruins the family and menaces the future of
the country."
It was propaganda like this that lead to a cascade of absinthe bans across Europe, culminating in 1915 in France (where it had skyrocketed to such popularity that it exceeded sales of wine) and Switzerland - the country of it's birth. The Swiss even included the ban in it's constitution. Absinthe was a victim of it's own success, as the most popular spirit of it's day, it was the target of teetotalers, wine lobbyists, and doctors who mercifully reported syphilis deaths as "Absinthe Disease".
Absinthe's absence generated a canon of fearful mythology over the next 80 years, with most of the western world simultaneously frightened and intrigued by the lore of it's wormwood-infused psychedelic effects on some of the greatest artists of the 19th century. Curiosity led to experimentation as adventurous souls wandered into herb shops to try to make the stuff themselves by soaking herbs in alcohol (bad idea!). After the ban was somewhat accidentally lifted in the EU in 1988, distilleries popped up making mostly poor quality versions due to lack of experience and the loss of authentic recipes.
It finally took chemist Ted Breaux to track down a pre-prohibition bottle and put it through a gas spectrometer in 2000 to reveal the truth about the green faire. Thujone, the neurotoxin in wormwood, was in fact a very minor player in the overall composition of absinthe - typically less than 10 parts per million. You would be dead from alcohol poisoning far before you'd be high from thujone. So what caused the notorious absinthe high?