A friend of mine who recently began playing reminded me of how confusing this was when I first started growing herbs.
When I plant an herb seed, I plant one seed. But the animation shows I've just planted four seeds. How exciting! My herb seed multiplied! I'm going to be RICH! I'm going to take over the WORLD!
But no. All I get is one herb. What happened to the other three seeds? I know I saw them when I planted. So either the animation is wrong, or my gardens always kill off 75% of my phantom seeds. Not to mention my plans for world domination.