What am I?

I watch over the people in the park.
See them talk, play, running...
I get farther and farther away from them
every second

They look up and see me move in different shapes
They call out, "Look it's dog, and that one is a heart"
Some of them think I am a fluffy cotton candy ball.

I have been all around the world
I've seen many memories that have been made
by the people.

I watched him pop that big question
that she has been waiting for.
I've seen her come back with a baby.

Sometimes I don't reach the top of the mountains
I live far up in the sky,
away from the other people.

Sometimes I like it when the people touch me.