Every race has their own myths about how life began, and unsurprisingly, most of them portray their own race in a good light. The Dwarves say the surface dwellers were unworthy Dwarves stretched out by demons, Humans say that they began all the other races, Elves only acknowledge other life existing at knifepoint, practically.
But the Trolls, their origin myth is quite self-deprecating. They were what was left over when all the other life was created, the congealed fluids from the Life Egg, given form.
They’re wrong, of course, but they’re closer than the rest of them to the truth.