No, this is not a post about the answer to life, the universe and everything. We already know that is 42. This is a post about reality and how real ones reality really is; or isn't. Interested? Read on...
One of the most popular ways of thinking about reality is : "Seeing is believing."
We now know that this is not enough. The human eye can only see a certain range of electromagnetic frequencies that we call the visible(how appropriate) spectrum. On either side of these frequencies we have the infra-red and the ultra-violet frequencies. Similarly, we can only hear a limited range of sound, taste a limited range of tastes and smell a limited range of smells. Our sense of touch and temperature is also extremely limited. We can only broaden these ranges of perception using instruments and scientific techniques. We will never be able to sense or perceive the entire universe in all its unfiltered glory. This may be a bleak prospect, but we have no choice in the matter.
Spiritual gurus, religions and some philosophically oriented individuals might urge you to look inwards as they believe that the brain/soul itself is a sensory organ which has no such filters on reality. They say that if one meditates strong enough and/or denies external stimuli one will be able to "KNOW" the whole of reality. Unfortunately, what a brain perceives when devoid of senses can just as well be a fanciful composition made from random sparks between the neurons. As for the soul, there is no such thing.
How then can we so arrogantly assume that what we can perceive with our senses and our gadgets is reality? This in essence is similar to believing in the geocentric model (the one where earth is at the center) of the universe. We now know that the geocentric model is incorrect and scientists are now working on the cosmological model.
At this point, we must agree that what a person believes to be reality is just a model (a very limited one) of the universe that they experience through their senses. Also, every person can and does have their own unique model of the universe. A very common example of this discord is the various religious beliefs held by people in the world. A christian has a model of the universe where god created it in seven days, a muslim's model includes allah and the prophet, an atheist's model leaves no room for god in it and worst of all, every single one of these people will argue vehemently that their model is the right one. So, how do we decide which model of reality to accept?
In his book, "The Grand Design", Stephen Hawking presents this concept in a beautiful and elegant manner. He calls it "Model-Dependent Realism."
So if we cannot by means of all our senses and technology perceive the absolute reality of the universe, we have but one choice: choose a model that best describes the reality. There is a very simple way to see how well a model describes reality, just check if it agrees with all the observations that we can make. If there is more than one model that agrees with all the observations, then they are both equally true. What if the model we have of reality agrees with all the observations that we can make, but not with reality itself? Well, do we really need bother ourselves with those aspects of reality that we can never hope to perceive? The very fact that we cannot perceive them means that they have no way of affecting us, so as far as we are concerned, they might just as well be fiction.
Now we have clear and logical method on how to choose the right model of reality. Unfortunately, the only system of beliefs (yes, in this context everything is a belief) that actually applies this method is Science. When Copernicus, Galileo and Kepler made observations that did not agree with the geocentric model, science scrapped the model (and the christian church tried to silence them.)
String theory is a model of the universe that is so different from the currently accepted model of universe that it turns our understanding of Physics on its head, but if it were to be proved, all the current models would be thrown out.
The same cannot be said for the models offered by religions or spiritual leaders. All these models require some amount of faith. They either require us to disregard the observations that contradict them or make no observable claims. For instance, if I were to propose that we are all a mere figment of some supernatural being's imagination, there would be no evidence for or against this theory. Also, this theory of Juju-Fantasy is absolutely useless as it does not further our understanding of reality in any way.
tl;dr : If you want to understand reality, throw in your lot with science, they are the only ones who are actually working towards it.