For humans, the present has always mattered more than the past. They spend little time exploring their origins. As far as they are concerned, they have always been here. (Older races raise an eyebrow at this assertion, but even the elves must admit that human tribes were well established when the elves discovered them.)
In contrast, dwarves have always been curious about their origins. Their oldest dwellings and relics contained hints at an origin myth, but only after their recent arrival upon Kalimdor did the dwarves see the larger truth behind their fragmented legends. Based on scattered ruins they discovered in the wilds of Kalimdor, the dwarves were apparently created by a now-vanished race that ruled the world in ancient days.
Incredible as this possibility is, it barely answers one mystery while giving rise to a host of questions. Who was this ancient race? Why were the dwarves created? What did these titans intend for them to do and should they be doing it? What were their creators like, and what happened to them? When they disappeared, why were the dwarves left behind?
Still, the dwarves' practical nature does not lend itself to blind worship of a progenitor race, regardless of how compelling the evidence may be. They rely upon measurements, mathematics, and the work of their hands. Rather than taking the measure of their creators on faith, the dwarves have embarked on a mammoth investigation of their past.
This evidence of titan progenitors has awakened a powerful excitement within the dwarves of Kalimdor. They rush out to explore the world around them, searching for clues as their time and resources allow. Any possible piece of evidence is studied, tested, and passed on to another dwarf for examination. The information piles up, the theories are tested and shared, and the base of knowledge grows.
The other races look upon the dwarves' efforts with everything from bemusement to treasure-seeking avarice to concern. Some are as curious as the dwarves themselves, while others worry that seeking hidden mysteries may awaken something primordial and dangerous.
The true origins of the dwarves
Somewhat unbeknown to the dwarves, the titans created the earthen — ancient ancestors to the dwarves — to help shape the world of Azeroth after they were gone. When the Well of Eternity imploded, causing the Sundering, the earthen were deeply affected, feeling the pain of the earth as if it were their own.
They retreated to their places of their origin — the titan cities of Uldum, Uldaman, and Ulduar — and hibernated for almost eight thousand years. When they awoke, they found that their powers over stone and earth had waned and their rocky hide had softened to smooth skin due to the Curse of Flesh — they had become dwarves.
Those who had awoken from Uldaman migrated to the snowy mountains of Dun Morogh and built the city of Ironforge. However, some of the earthen had devolved into troggs, also due to interference from the Old Gods). Their strength was still in their grasp, but the same cannot be said about their intelligence.