Why is this the answer?

The answer is mist because this clever riddle uses fun word pictures to describe something that is everywhere and nowhere all at once. Mist is actually a special type of weather that looks exactly like a cloud, but instead of being high up in the sky, the cloud has settled down right on the ground with us! It is just a cloud that loves to visit the earth. Let us look at the first clue: "A hill full." Imagine you are hiking up a great, tall hill in the morning. When the mist rolls in, it completely covers the whole hill. It is so thick and white that the biggest hills or mountains are totally surrounded by it. The mist is literally filling up the space around the entire hill, making it full of fog and making everything look soft and mysterious. This is the first picture the riddle wants you to see. Now, let us look at the second clue: "a hole full." If you have ever been in a low valley or a dip in the road, you know that the mist can settle there too. Even though it covers the big hill, it also goes into every small space, like a little hole or a deep valley. The mist is like a super friendly visitor that wants to fill every space it finds, whether it is a giant hill or a tiny low spot in the ground. The last part of the riddle is the trickiest and the most fun: "yet you cannot catch a bowl full." This is the best clue! Try to catch a handful of mist. You cannot! If you try to scoop it up with a bowl or cup, it just slips right through your hands and the opening of the bowl. Mist is not like water from a sink that you can collect. It is actually made of millions of super tiny, microscopic drops of water that are floating in the air. Since they are so light and floating, you can walk right through them and you can never, ever trap them inside a bowl. This is why mist is the perfect answer!