Many people take the opinions of others as law. This may be fine, because you're learning something from others, but what if the person is wrong? Well, then you get a wrong opinion and can act accordingly.
I'll give you an exaggerated example. Hitler in his time told people that "The Jews are a people of robbers." he said that Jews have big noses... Well hundreds of thousands of people trusted him when he said this and also much more vicious lies about Jews. As a result, the Nazi's were so full of lies that they killed off Jews by the masses.
Instead of believing opinion, one might just want to look for himself and get the real information. Your eyes are the last to betray you.
A much smaller example is someone telling you that "Joe Blow is so mean," you may think immediate that Joe is a bad person or may not want to associate with him. However, the best thing to do is simply find out for yourself. Talk to Joe and see what kind of person he is. He may just be a nice person and not have a single bad thing to say.
If you simply look instead of listen, you may find a lot of the things that are spread around are actually not true, and you will have a very clear vision of the world. Who can tell you something is different than to what you saw with your own eyes? And if they did, you would know not to believe that.
You can also always find out by checking out a book at a Public Library or buying a book, such as at Barnes and Noble.
