You can never really prove the proposition that “all swans are white” even if you spot a million of them and all of them turn out to be white. But you can certainly disprove the proposition that “all swans are white” by sighting a single black swan. Nassim Taleb’s explains Karl Popper’s powerful idea of falsification in his book, “The Black Swan.”
Evidence that confirms your exiting beliefs is not as powerful as evidence that disconfirms those beliefs.
Great scientists like Richard Feynman agree. He once said, “If you’re doing an experiment, you should report everything that you think might make it invalid — not only what you think is right about it. Details that could throw doubt on your interpretation must be given, if you know them. The exception tests the rule. Or, put another way, the exception proves that the rule is wrong. That is the principle of science. If there is an exception to any rule, and if it can be proved by observation, that rule is wrong.”
Learn to recognize and respect disconfirming evidence if you want to make good judgements. Most people do just the opposite. They seek out evidence that proves them right and ignore or discard evidence that proves them wrong.
Don’t fall in love with your ideas.