To question reality is to make the most amateurish mistake in all of philosophy. The question itself is meaningless. I will now illustrate why.
First, let's establish that "reality" is, by definition, that which actually exists objectively. You can compare it to "perception," which is that which seems to exist, based on our own ability to experience it via some combination of the five senses and true-and-valid logic.
Thus, the real question is: How do we know that which we perceive truly represents reality?
To answer this question, we merely have to observe that every new piece of knowledge you acquire changes your perception of reality. Whenever you receive any new piece of information, either by perceiving a new experience or engaging in irrefutable logic, your understanding of the world around you becomes more accurate. (Here, I assume that "information" is true. False beliefs will also change your perception for the worse, but that fact is irrelevant to the topic of today's blog post.)
Because every new piece of knowledge improves the accuracy of your perceptions, then it is obvious that one will only ever perceive reality when one possesses all knowledge, i.e. when one is omniscient.
Does an omniscient being know what she will be doing in exactly 677 hours, 23 minutes, and 7 seconds from the present time? If not, then she is not omniscient. If so, then she is thus able to alter that event, which implies that that which she previously knew was not the truth; hence, she is not omniscient.
The truth is, omniscience is impossible. Obviously, everyone knows that they themselves will never be omniscient, but as I have just shown, omniscience itself does not exist. There is no such thing as knowing everything.
If omniscience is impossible, then it is impossible to perceive reality. This does not imply that there is no reality. Nor does it imply that perception is reality. Instead, all we really know is that there is always a gap between our present knowledge and a state of total knowledge. And that is all we will ever know.
If the question is whether there is a difference between perception and reality, then we all know the answer: of course there is.
If the question is whether one, true, objective reality exists, then the question itself is meaningless. The word "reality" is basically defined to be that which really does exist in an objective way. So asking whether that which is defined to be true really is true is essentially questioning the definition of the word reality, or else the meaningfulness of it. Does the set of all knowledge which, by definition, is impossible to acquire actually exist?
What does something that is invisible look like? What does a physical vacuum smell like? What happens at one degree less than 0 Kelvin? If the universe could view itself in a mirror, what would it look like?
All such questions seem interesting upon casual examination, but close examination reveals them all to be paradoxes. That is, they are meaningless by definition. That which is invisible cannot look like anything; if it could, then it would not be invisible. Vacuums smell like nothing, because vacuums are by definition states of nothingness; but more importantly, human olfactory sensation cannot exist in a state of nothingness, because our mere presence would alter the smell of the vacuum and render it no longer a vacuum. 0 Kelvin is defined to be the absence of temperature; there is no such thing as "negative existence;" there cannot be a -1 Kelvin. In order for the universe to see itself in a mirror, it would have to look through space and reflect light; since all space and light is contained within the universe, then it could never be seen in a mirror.
Again, all of these are merely questions in which the definition of something is assumed to be the opposite of its definition. In philosophy, we call these questions paradoxes.
Questioning reality is just another example of a paradox. It is not a clever question, it is a meaningless contradiction.