Almost a hundred years ago Edwin Hubble was studying the Andromeda Galaxy and discovered that it was not part of our Milkyway Galaxy. It was thought at the time that the universe was no bigger than our Galaxy, but this discovery changed this in 1923.
It is strange to think that not that long ago our view of the universe was so small in comparison to how we view it today. This to me highlights how open we need to be to new information. We can feel certain about something until it is proven wrong. It was once thought that the Sun moved around the Earth and that the Earth was flat.
Problems arise when we hold on to our certainty, even when new information arises to disprove what we have been certain about. Openness to change and the humility to change our views is much more useful in life than blind certainty.
The Fullfilment Project 