Yesterday night, I saw my friend John. He was in a class with me at school, and I realized I was dreaming, because I know it was Friday the day and that the school week was over.
I checked my watch 3 times, and realized I was dreaming.

Okay, this is the problem: I tried to change scenes.
I tried to imagine a scene I was in, and could feel that I am busy blending into the new scene, but the dream did not let me go.

The scene I wanted to go to was a scene I dreamt of several times.
It has green trees, and several times I dreamt of this scene, I even drew a picture of it, and want to go back someday in a dream.

How could I go to scenes I want to?
I lose my lucidity whenever I want to change scenes.