Baking analogy at work today: Not every baker can bake wedding cakes.
I have bakers who are incapable of baking wedding cakes because they are just not sharp enough to pick up the skills. They get upset at baking the run-of-the-mill cakes all the time and slack off, while dreaming about baking the big one. The rest will then have to help with baking the normal cakes they're slacking on, and in turn get pissed off too.