Took a long time to level from 1 to 60. Around a month if you'd knew where to go.
Questing zones never really had (enough) quests for the indicated levels you could spend... leveling there. Take Arathi Highlands for example, a lvl 30+ zone with only elites to kill in Stromgarde and lvl 35+ mobs. A lot of fun if you just enter at lvl 30 yourself.
Grouping up to kill elites was pretty much mandatory if you wanted to defeat one, not in all cases, but most definitely the vast majority.
The 60% mount was available at lvl 40 and costed a ton of gold, not even mentioning the 100% one at lvl 60.
Mana wasn't a cosmetic blue bar like it is today and energy didn't restore every second but just a chunk after a few seconds.
Only one spec sort of actually worked for any class, or some weird mix of 2 tree's. But there was always at least one tree you could pretty much throw out of the window. This changed a bit over time as more specs became a little more viable, but most of that truly had an effect on raid setups during TBC.
Battlegrounds came in later, AV and WSG were the first to arrive and that "killed" (not very true on healthy servers) world pvp. No group/raid/battleground finder, you actually had to move your ass over the places where you could sign up for said BG and make a group through chat and then move to the dungeon.
You even had to make a group inside a Battleground before it started for a while, either resulting in 2 uneven groups, or if you were lucky one would simply invite everyone.
Winterspring being the most finished zone to get to lvl 60 still had you move all over the damn world to do quests. When you look back it was quite unfinished. The lack of quests in many zones that are considered proper questing area's today, just wasn't there.
I miss my old server, Sylvanas-EU. One of the very few realms that remained very balanced in Horde/Alliance ratio for a much longer time than most other servers. Now it's just an Alliance infested server with 5 Horde players (over exaggerating but you get the idea), and my Undead mage is still there today.
Some raiding guilds I've played in during that time: Serenity, Ascend, Event Horizon and Federal Bureau of Moo (best guild on horde side together with Affliction).
Vanilla WoW was great fun for it's time. At the same time I don't really care if they would implement it again. It won't be the same as it was back then anyway. With that I mean that it won't feel new and fresh. People on the internet were generally different in those times as well and not just in WoW. Less trolling and screwing each other over and just more cooperative, helpful and meaningful.
Vanilla was quite the hardcore experience, and I'm glad I got to experience it and managed to understand it enough to end up raiding as a 13 - 15 year old kid.
Playing it a few weeks after launch and I still play today, although with quite a few breaks in between, I still think it's the best game I have ever played. A game that still manages to entertain me after (almost?) 13 years, is crazy. Casting aside the issues I also have with some changes.
The most silly fact is that when I bought the game I didn't even know it was an MMO, rofl. I always thought it was a Warcraft 3'ish game where you directly control the hero character, instead of a RTS overview.
A time where we could laugh at pictures like this: