Your experience is drastically hindered by the fact that the game has a very good system for teaching people to play. It starts out ridiculously easy with no skill or thought whatsoever (and modern day raiding continues the mindless button mashing, PVP is where skill comes in to play today, aside from a couple of ridiculous mistakes made by blizzard in recent days). You start with 1 or 2 skills, and the game tells you how to use them. You practice using them with little to no risk of dying so that the game isn't frustrating for you because you are new.
From there after leveling up and gaining knowledge in how to use the skills you started with, they add another skill for you to be able to use, at first you don't really need it, or it may seem useless, but as you progress though the levels you will realize the necessity of the skill and implement it into your play style. This continues to happen throughout the course of the game so that by the time you reach level 60 (or 70, 80 or 85) you are familiar with all of the skills and how to utilize them to your advantage in combat (PVP, raiding is hardly something to talk about these days)
The game is daunting, and they realized that, instead of slapping you in the face for picking mage or warlock and putting 80+ spells in your book with tooltips for you to sit down and read and analyze and re-analyze and overthink they made the game so ANYBODY could pick it up, and learn to play it PROGRESSIVELY. Of course when you start out with 1 spell, and only learn 3-4 more by the time you 'cap out' the game is boring and mindless.
Unfortunately, you chose what has become the most boring class to level from 1-20. Mage from 1-10 is FIREBALL. Mage from 10-15 is FROSTBOLT->FIREBALL SPAM. Mage from 15-20 is Frostbolt->Fireballspam->OSHI hes close frost nova->Frostbolt->Fireballspam.
Please, don't judge the whole game based on the first 20 levels, and don't judge it based on raiding.
I played the game heavily in 2006,2007, quit for most of BC (bad decision), came back near the end of BC and played relatively casually (We downed current content, but we only raided twice a week, this includes Sunwell and Ulduar while it was new and NOT NERFED. I also was successful in Arena) And I would hate to think that someone would critically assess WoW as the game it is today, Cataclysm is a new game, its no longer World of Warcraft; everything has changed, and its not as fun as it used to be - which is why I am quitting at the end of this PVP season. Don't get me wrong, its probably still appealing to console gamers and achievement whores, and it certainly holds some entertainment value, but having played WoW back then, and seeing it now is depressing.
TL;DR: Levelling from 1-59 is basically a tutorial on how to play your character, rather than have you sit there and read a bunch of tutorial messages and spam you with details about all of the possible spells for your character, they teach you the game WHILE YOU PLAY IT. Its a huge game, and every class has a massive number of skills available to them, it would be overwhelming for some people to try and absorb that all at once.