Grace of light and shadow
reality is based on perceptions that could be different in everyone.
Reality is not based on perceptions nor is it different for everyone. Reality remains reality no matter how one perceives it. A tree is still a tree even if no one is around to notice that there is a tree. Things don't just pop into existance as soon as a person perceives them. They were already there.
Grace of light and shadow
saying yours has to be right or that it is impossible for this to be is short sited because no one can consider every factor in any situation.
An idea, or as your put it, a particular perception is correct when the evidence, that is not reliant on being perceived, backs it. When the evidence does not, it can be confidently concluded that the evidence has not been found, or the idea is simply false.
Grace of light and shadow
a crazy person could see a normal world that doesn't actually exist so we can safely say that we could all be doing the same.
Are you seriously considering that what delusional people see has some basis in reality? I suffer from psychosis. I know what it's like to see, hear, taste, smell, and feel things that aren't really there. The difference between you and me is, I can admit it's not real.