First-year physics students think they understand relative velocity until this hits them. Throw a ball at 30 m/s from a truck moving at 20 m/s and suddenly you've created a projectile moving at... wait for it... exactly the speed of light? That smug Gru face is every physics professor watching students realize that classical mechanics breaks down spectacularly at relativistic speeds. The punchline isn't just that 20 + 30 ≠ 50, but that no matter what you do, you'll never reach the cosmic speed limit of 299,792,458 m/s. Einstein's equations just sitting there like "I told you so."