The cold war ended, and the berlin wall fell, and the soviet union fell apart, in the late eighties. And the nineties were the first 'digital decade' So things did indeed change alot around that time. Both socially and technologically.
So you could make a case that was a pivotol year-now that I think about it. It may not be just an artifact of you being born that year.
The first world war resulted in the rise of communism, and begat the second world war a generation later. The second world war led almost immediately to the cold war. The cold war lasted for two generations (the late fourties until the late eighties). So when it finnally ended that was the true end of world war one- or of the issues set into motion by world war one.
I had similar thoughts when I was your age- but pushed back in time. My parents grew up in the "inter war" period between the world wars: movies, radio, the jazz age, the great depression. I and my boomer contempoararies grew up the post second world war age: TV, rocknroll, the space age, the cold war, To me the year 1945 was a huge boundryline in time (much like 1990 is for you). The era before the end of world two seemed as foriegn to me (a teen in the late sixties) as a foreign country. And that was during tumult of the late sixties - civil rights- vietnam- and age restrictions when going to movies started- when the world was being remade again ( a generation after world war two). I came up with the theory that history went in 25 year cycles( the aproximate length of a generation)- two decades of deceptive calm- followed by a half decade of sudden change. The first world war ended in late 1918- then there was two decades of deceptive calm- then the world changed by the war (39-45). Then there was 20 years of the deceptive post war calm that ended around 1965. Then you had the upheavals of the late sixties.