As a result, my first time through the game, I barely paid attention to what I was doing, who I was fighting or why. It wasn't until I got to Molten Core that I started really thinking about what was going on. How did Thaurissan summon Ragnaros when he clearly had not intended to, and what was the Firelord up to? At the time, Ragnaros seemed astonishing to me, an entity of pure fire older than the whole world. The war between his Dark Iron servants and the dragons and orcs atop the Blackrock Spire became a central part of my game as I moved on to Blackwing Lair. I started paying a lot more attention to the dungeons and quests I was running.
Once we hit Outland and I got to Shadowmoon Valley, I ran the Cipher of Damnation quest line (a quest that is all I could hope for in a long quest chain, frankly), and the end of that quest line raised so many questions that I often point to it as the beginning of my lore nerd status.
What is the Cipher of Damnation? If it's the spell Kil'jaeden taught to Gul'dan that he used to raise the Hand of Gul'dan and sever the connection between the orcs and the elements, it's clearly not all it can do. Since using it summons Cyrukh the Firelord and since Oronok Torn-heart says it has been used "in the history of our worlds," I am now convinced that the Cipher is the spell that Thaurissan used to summon Ragnaros. But where did he learn it? It was also the spell Kael'thas used to try and summon Kil'jaeden through the Sunwell, which continued past Kael's death in Magister's Terrace.