It's called lucid dreaming. So yes sometimes people can control their dreams. But even people who lucid dream don't typically lucid dream 100% of the time. Lucid dreaming is awesome and is like being the God of your own world as people who lucid dream often reconstruct everything in their dream world.
If you want to learn more about controlling your dreams, look up "Lucid Dreaming" on Google. For those who don't know what lucid dreaming is, it is a state of mind during your sleep where you can literally control your dream. You can control what you see, hear and feel during a dream. This state of mind is even used as a therapy to prevent nightmares. For those of you who are in disbelief, I suggest you try it for yourself. There is no risk, and you'll be sleeping the whole time anyways.
Actually, I haven't seen "Inception" yet, so ignore that. Anyways, "Lucid Dreaming" is a rare, actual phenomenon that occurs when dreamers realize they are in a dream. Then, they can proceed to control what happens in the dream. People have even been able to obtain this state of mind through various practices, including developing a habit of checking if one is in a dream at regular intervals. There we go - a dream is controlled. This resolution is confirmed to be true.
It's called lucid dreaming. I've never had one but every one who has clearly says they are in control. Once you know you're dreaming, you can gain control of it. Plus dreams are a result of previous thoughts and what you did before sleeping. If I go to bed thinking about a particular thing, I'm more likely to dream about it.
People often dream about the last conversation they had before going to bed, or the last movie or TV show they watched before falling asleep. So, there's a good chance that dreams will be pleasant if you fill your mind with positive things before bed. Also, reducing stress and anger will make for a more restful sleep, which leads to better dreams in many cases.
Your dreams are based around what you are thinking about and what you feel on a day to day basis. While you may not be able to control each and every aspect of your dreams, if you choose to think about positive things rather than negative things, you are much less likely to have bad dreams, for example.
Dreams happens at a subconscious level that we cannot really affect in any direct way. We do not even remember half of the dreams we have. Although science may one day help us understand the content of our dreams, we do not have enough information yet to know how they are controlled.
No, it is not possible to control your dreams. Dreams are our way of dealing with emotions and issues that occur during our waking lives. Society requires us to behave with professional courtesy and tact in our dealings with each other. It can be emotionally draining to maintain a socially acceptable attitude some days. When we have really trying days, we are more prone to have dreams in which our emotions and imaginations run free trying to resolve the days issues for us. This is when we are most prone to have nightmares or other bizarre dreams – and nothing we can do to control them.