No, not the "gay" you were thinking of , nor The '90s you were thinking of, for that matter. You see, back in the earlier half of the twentieth century, people became enamored with the s. It was where what we now recognize as "decade nostalgia" was born, and The Gay Nineties became a popular setting for films of the s, the s and, to a lesser degree, the s and s, by which time it was seen as that innocent age before World Wars and atomic bombs. If you lived in this time period, you were generally fortunate as long as you lived in wealthier countries of the world, as it was a time of relative peace see below. On the flip side, if you were born in this decade, you would most likely live long enough to see and probably be involved in the First World War , The Spanish Flu , The Great Depression , the rise of totalitarianism, wartime genocides, and the Second World War.