Why Do Infinity and Half-Infinity Behave Differently?

Imagine you have two jars, one with candies and one with jelly beans. If you keep adding more candy or jelly beans forever, both jars will eventually be full of infinite treats. But if the number of jelly beans is like a never-ending stream from a river, while the candy just keeps being added one by one, it might feel like there’s more jelly beans than candies, even though they are both infinite.