I’d be 24, spending my first full year out of college working and living abroad in Budapest at a business newspaper as the chief (and only) photographer. It was an especially interesting and exciting time of my life. I’d be making a hell of a lot less money than I am now, but living for peanuts in one of my favorite cities in the world, going out every other night, and meeting some of the most creative and off-beat individuals I’ve ever had the pleasure to know. It was a time of my life where every day felt like an adventure and anything was possible.
1999 was a year of major significance for me:
I turned 29.
My new business started gaining speed and we hired our first employees.
I got married to my beautiful bride.
It was also my last full year before I got sick, the after effects which I live with to this day. 1999 was probably the happiest year of my life to that point. Luckily it was not the high water mark and other than thinking of my wedding day every time I look at my wife, I have had many great years since.
In December of 1998 I had become a first time mother. I spent 1999 in a fog of nappies, being simultaneously the happiest and most panic stricken I had ever been.
Shitty year…
I’d be back home after my failed bid to move to the US. Well, I had moved there, but I’d come back with a Masters without Thesis instead of the planned PhD, and I’d come back to help care for my dying father (read, to be the actual primary caretaker) partly out of filial duty and partly out of my employers deciding it would be “best for all involved” if I went illegal.
On July 24th, first day of the local fiestas, I went to see the opening ceremony (the smaller cousin of this). I saw my brother, his gf and their closest friends ahead of me; Bro turned back and glared at me (at the time he was in the middle of a very long period of blaming me for everything that’s ever gone wrong for him); one of the friends wondered what had happened, turned and exclaimed “oh, it’s your sister! Hi, Nava! Come join us!” Watching the ceremony with them and then going for some tapas before excusing myself to go cook lunch was the extent of my partying for that year.
Not my worst year, but definitely not one I want to go back to, specially in terms of partying! High school wasn’t a time I’d want to go back to… but it did have better parties 
I’ve just turned 25.
I have pleasant job in a very laid-back company where most of my collegues and about one third of our customers are around the same age (22-35).
I have my own place. I’m not rich but I make enough money to go out several times a week and go on a nice holiday once a year without worrying about financial stability. I can even save a not insignificant amount of money.
As far as relationships are concerned, it’s been wild. And fun. The best year of my life in that respect, by far. I don’t know it yet but the 2000s are going to be much less wild and fun. It’s like I used up half my life quota for casual sex between May and November 1999.
It means everyone would be wearing quasi-futuristic clothes, possibly uni-sex. And wigs - wigs would be worn as fashion statements by both men and women. Cars and buildings would look like they were designed by Syd Mead. Everyone but me would have British accents. Music would have a retro-techno feel, with classical overtones.
This is what the term meant to me in 1982.
And I would have hoped that by then that Prince albums would have been consigned to the bargain bin of history. Apparently, none of my vision came true. 
In January of '99, I turned 45. We were living in King George, Virginia, and my daughter was in middle school. My dad was still alive, and I hadn’t yet discovered the Dope, but I was surfing dial-up style, trying not to exceed our monthly total of minutes.
I ended the year mocking the coworker who was hoarding jerky and ammo against the impending doom of Y2K, and husband and I celebrated our 16th anniversary. OK, celebrated is too fancy a word - we hit 16 years together. We didn’t really start doing anything for our anniversary till 2004, and even then, it was just going out to a nice place for dinner.
Anyway, not a whole lot of partying in '99.
6 months? GAH!
gosh all you youngsters!
Oh I was 40!
Assuming we’re talking about partying like it was NYE 1999, I was 27 at the time, single, and had moved from Houston to the DFW area (Plano, actually) in August of that year.
I was working in a job that I grew to dislike a lot, but at the time, I wasn’t feeling pigeonholed or like my immediate boss was an idiot just yet.
I don’t think I did much of anything that NYE; while I had some friends in the DFW area, there wasn’t a big party or anything that we were invited to, so we just hung out at a friend’s apartment and nothing interesting happened whatsoever.
Living in US with the love of my life and her kid and travelling about meeting friends I knew from a very busy mailing list. I stupidly came home, injured my back in such a manner I was advised to never fly again and it would be a long time off work so I never got back there. She came out to Australia for our goodbyes.
So either deliriously happy and settled or completely adrift in sudden and severe disability with my heart ripped right out of my chest getting used to being rather poor financially.