When you are asleep, I'm not sure you can control your dreams. But, when you are awake, there is no limit as to what you can dream. Now I suppose we all have dreams. Some people call their dreams 'visions'. Or maybe a dream is a vision with your eyes closed? As for me, call it what you want but I got them!
I know that most dreams are just dreams and not a vision of my future. But I am still a dreamer. I suppose it helps me get through the realities of the day. They give me something to look forward to - something to work toward.
People without dreams (the daytime kind) are people that are bound to live a boring life...unless they already have everything possible, and have been everywhere possible, or have met everyone possible...which I don't think is possible!

Allow yourself to think outside the box. Don't set limits on the possibilities. Don't let anyone spoil your dreams. Your dreams/visions maybe from God and not your own wants and desires. It seems to me that there were a few people in the Bible that changed the world they lived in because of dreams or visions they received from the Lord or His Angels...Abram, Jacob, Daniel, Paul, etc.

Dream On!