What's the truth?

I recall watching a short video that challenged many of the facts we were taught in school as children. According to the information in the video, Columbus did not travel across the ocean to prove that the earth was round. By 1492 most people knew that the earth wasn't flat; they just didn't know its size. That was what motivated Columbus to make his now famous voyage. Whether or not the video was accurate only begs the question of what we accept as being the truth. What is true today may be a myth tomorrow. Yet we may base the actions we take today on that possibly mistaken belief.  On a more personal level, what truths have we created for ourselves about our past that are affecting our present and our future? Have we fabricated our own version of the Columbus story as an explanation for an event and then carry it with us coloring the decisions we make? I can think back in my own life to situations I believed to be true with 100% conviction, only to learn later that I had missed the mark completely. I wonder how many lives had been affected, including my own, by what I had believed to be true. Perhaps watching this video was an opportunity for me to consider the veracity of the stories I have created and allow myself to be open to other versions. In some cases I may need to make amends for the content of those stories. What is a truth that you have held onto for years and what happens when you hold it up to the light of scrutiny today?