The Probability of Intelligent Life Existing in the Universe

i i am convinced that intelligent life could be quite common in our universe. It's just that we haven't found it. Maybe we are too primitive to be able to detect evidence of intelligent life, or whatever it is. But the likelihood of such intelligent life having visited the earth is very unlikely. The probability is not zero, but it's close to zero. Why is it always the united states where you get these u f o sightings? Is it? Is there something really special about the people whoo live in us? So that's one thing that doesn't make any sense.