Imagine you have a basket with some berries in it. Now, you want to describe how many berries are in the basket, but you can't count them because you're too lazy. So, you write a sentence that says "The number of berries in this basket is less than a thousand".
But then you think, "Wait a minute. If there are really 999 berries in the basket, then my sentence is true. But if there are 1000 berries or more, then my sentence is false. But my sentence says that the number of berries is LESS than a thousand, so it can't be 1000 or more! But if it's less than a thousand, then it must be 999 or less! But that means my sentence is true! But that means there can't be 1000 berries or more!"
So, you're stuck. Your sentence, called the Berry Paradox, seems to be true and false at the same time, and you can't decide how many berries are in the basket. It's like when you have two candies but you want to give one to your friend without breaking it in half. You just can't do it!
The Berry Paradox is a puzzle that shows us that sometimes, even when we think we've described something clearly, we can still get confused and not know what to do. It's like having a brain teaser that we just can't solve. But that's okay! It's important to keep trying and to ask for help when we need it.