I think therefore I am . . . right?

I was reading Sarah Knox's blog last night, and I felt a little overwhelmed. Maybe it was because it was really late and I was tired, but her contemplations of everything happening in the mind made me wonder if I was actually there reading, or if I was dreaming I was reading, because I had seen it earlier that day- I had skimmed it, and maybe I was just filling in the blanks that I couldn't remember. She mentioned how powerful dreams can be- how you can dream about someone or something and the emotions attached to that dream splash into "real" life. But are we truly real? Derrida had those same issues back in the day, pondering God, the world and his own existence. He came up with the famous, "I think, therefore I am" and a bunch of other math/philosophy stuff. It's kind of subjective though. I think, sometimes, but that reality- the stuff I see is different from what others think and see. Is there an all encompassing "reality?" I think it's easier to share a dream than the "truth," whatever that is. Maybe the world itself is the dream that we share. Reality lies only in the mind of the individual, so those things we do to express that reality is our attempt to communicate it to others, but it doesn't always stick. Of course, this is only speculative. It may not be true. Or it might. Does that really matter?
I read an interesting essay about the red and blue pill that Neo has to choose between. http://www.arrod.co.uk/essays/matrix.php In a few classes I've had with the same professor, he's asked us which one we would take, the red or the blue. The red tells us that secret- "What is the Matrix?" and the other lets us stay in the dream world, asleep. Do we really wake up though? I think we may just find ourselves in another layer of another man's dreams. It could be that the reality, I though existed in each person, is really just my own dream. Or maybe all of those realities, if they do exist, are just dreams that globbed together to make one huge dream that we all live in. We are deceived, delusional, dreaming. Or maybe those dreams are the only reality that exist, but we are too scared to explore that realm. Does your head hurt yet? Mind does.