Glory
You won't personally get to see the delighted looks on kids' faces as they open the gifts you've hand-crafted, but you'll know they're there. And it'll somehow make all of the grueling hours for incommensurate pay well worth it.
Actually, come to think of it, you've probably never seen a human child at all. What do you care if they're happy or not? Why are you slaving away to bring happiness to a race of ingrates who barely even acknowledges that you exist?
Er...um...yeah, so...you'll do it for the kids.