What is A single observation doesn't prove a theory?

A single observation doesn’t prove a theory because one example isn’t enough to show something is always true.

Imagine you're looking for your favorite toy in a big box. You reach in and pull out a red ball, that’s an observation. But just because the first toy you pulled out was red, it doesn’t mean all the toys are red. Maybe there's also a blue car or a yellow dinosaur hiding inside!

Let’s say your friend says: “All the cookies in the jar are chocolate chip.” You take one cookie and eat it, it is chocolate chip! But that doesn’t mean every cookie in the whole jar is. Maybe there's also a sugar cookie or a peanut butter cookie waiting for you.

So, just like one toy or one cookie can't prove everything about the box or the jar, one observation can't prove a theory either, it’s just a clue to help us guess what might be true.