Through loyalty to the past, our mind refuses to realize that tomorrow's joy is possible only if today's makes way for it; that each wave owes the beauty of its line only to the withdrawal of the preceding one.
People sometimes hold themselves back because they want to use racism as an excuse for them not being able to achieve what they want to achieve.
What has always surprised me when I walk into a bookstore is the number of books that you can find that are written with certainty. The authors tell some story as though it's true, but they don't have any evidence that it is true!