Is it normal to doubt reality?

I think most people doubt reality at least once in their life. If it happens to you really often, to the point that you dissociate from the "real world", then it becomes a problem though.

I'd like to refute your statement though (about the "I think therefore I am"). People in our dreams, our imagination, and in video games can think, but they aren't real. So how can you be sure you're real just because you think).

Dream is akin to reality. But reality is real because law of cause and effect comes to action. I think I copied the answer from Einstein, but I can't remember his actual word.

My idea, in reality, law of cause and effect is external, but in dream, law of cause and effect is internal.

You know this is very good thinking. In fact perception is only what you see. There is nothing regulating what we see. Like the matrix you could simply be in a dream state and there is something different going on.

I think the only reality we can be sure of, is the reality in which we live. If you feel the reality you live in is not real, than what is "real". If you can: see, breath, feel, than reality is whatever you choose to perceive.

this sounds an awful lot like the movie radio am i right? or remember the titans? any given sunday? the replacement? We are marshal?

This sounds like depersonalization disorder to me.

Check it out: http://en.wikipedia.org/wiki/Depersonalization_disorder

You're lacking physical pain.

Go out and bang your knee on a metal pole. Suddenly reality will seem a lot more real, like it did for your great-grandparents when they went hungry in the depression.

Thats normal. Good things to think aswell, those thoughts led me to thoughts on since reality is real, how did we come to be in reality, and how was reality itself created. Did we in time randomly evolve and happen to be here, but for what purpose. I find that we must have been placed here, created by God in the reality he made for us, which gives us a purpose. Where if we were he by random in a random reality with nothing after death, what would be our purpose? Think through it, God really does make sense in the perspective. Logic is such a great tool, use it wisely though, check your logic after you consider it, false logic is deadly, but correct logic, well its life changing.

You're watching the Matrix too much.

OH YES I KNOW! I hate having those thoughts because you have no answers.

I know exactly what you mean, and if I think about it and start wondering if I exist or not then I feel freaked out and feel like i'm falling!

No man, that normal for us whole have deep thoughts. Trust me I'm real too. haha You expressed that so well that it kinda freaked me out a bit.

Totally normal, the greatest thing is the "trap of solipsism", look it up, it basically proves that we can never, ever test or prove whether what we percieve to be real is reality, and says the individual's mind is the only one in existence. As Descartes says, there is only one thing we can know for sure; "cogito ergo sum", I am thinking therefore I am. (although this can be attacked on the "I" of the statement, so it is more definate that "something is thinking, therefore something exists")