For example, I used to think of 1990 as the last year of the 80's rather than the first year of the 90's. My logic was that since the '01 year of a century is really the first year of the new century rather than the '00 year (meaning that 2000 was still the twentieth century), it made sense to me to apply that same logic to decades. For that reason, when I began posting here, I made a post about Depeche Mode's Violator album in the 80's section and then saw that it was swiftly moved to the 90's section. I've slowly adjusted to the standard that is applied here and I accept it whenever I post, although it still feels a bit inconsistent to me to say that the year 2000 is part of the same century as 99 of the 100 years that begin with 19__, and yet say that 2000 is not part of the same decade as 9 of the 10 years that begin with 199_. So, did anyone else feel the same way?

A decade is actually a row of 10 years, no matter when it started. 1991-2000 is a decade as well as 2005-2014 or 1888-1897. If you call a decade the "80s", "90s" or "2000s", then the decade always starts with the 0-year and ends with the 9-year.

For centuries it's different. You actually count the past centuries and the result is what we call them (18th, 19th, 20th century...). That's not what we do when we talk about decades. Or have you ever heard people regularly talking about the 1st decade, 2nd decade and so on?

That's how I see it:

1900-1909 = The 1900s decade
...
1980-1989 = The 80s
1990-1999 = The 90s

1901-1910 = First decade of the 20th century
...
1981-1990 = 9th decade of the 20th century
1991-2000 = 10th decade of the 20th century

1900-1999 = 1900s
1901-2000 = 20th century

2000-2009 = The 00s
2001-2010 = First decade of the 21st century

The 0 year of most decades has more in common with the previous decade than the one its really a part of.  That includes 2010 which was pretty much the late '00s. 

The 0 year of most decades has more in common with the previous decade than the one its really a part of.  That includes 2010 which was pretty much the late '00s.


That's the pop cultural definition of decades. I don't know if that's what SiderealDreams meant. Probably not.
And to be honest: What about 1991 or 1992 in comparison to the rest of the 90s? That would also be more late 80s... So it's not only the 0-year that has something in common with the previous decade. You can't argue like that.

I just thought what if the counting of years would have been 5 years off? So that the 80s is 1975-1984 and the 90s 1985-1994 and so on; would that immensely alter our perception of culture? I think we have to watch out assigning pop culture to decades just because the years start with the same three numbers; or what if we had twelve fingers? We would have had dodecads.
Is this off topic though? Just some thoughts from the late evening.
As long as we remember that the year 0 never existed.

For example, I used to think of 1990 as the last year of the 80's rather than the first year of the 90's.


You're partially correct, the earliest part of 1990 was the last of the 80s. The early 90s began when Operation Desert Shield was announced. The true 90s did not really begin until 1993. In the spring of 1990, you still had specials on TV like The California Raisins Sell Out, neon orange converse hi top sneakers were worn and Bush 1 still had a high approval rating. By the end of 1990, the California Raisins disappeared , white Converse hi top sneakers with the new logo were in and people hated Father Bush because of the recession. However, if no part of 1990 ever happened, '89 served a good prologue to what was to come. Unfortunately, many members of society do not see things the way I do. Even in 1990, people thought we were in the 1990s already. That was mighty silly of them to think such a thing. The Saturday morning cartoons of the winter and spring of 1990 were the same ones from the fall of '89. Not much changed overnight from December 31, 1989 to January 1, 1990. There were some very 90s things to the start of '90. The clothes were the same from September of '89 to June of 1990. Some people call 1990 "a watered down 1989". I disagree, as evidence I could bring up the New Kids on the Block. In 1990, the New Kids were on top of the world. They had dolls, comics, McDonalds plastic cups, Coca Cola contests and almost an NES game. 1990 was nothing like 1989, for the most part. Teenagers had the same attitudes from the late 80s for all of 1990. I will agree with 80s fans on one thing; 1990 was the cheesiest year in history. When you look back at what happened in 1990, it doesn't scream 90s. So, 1990 was a two sided year from beginning to end.