I promise if an alien shows up at my door, shows me valid ID (not a Martian drivers license...I'm pretty sure those can be faked), takes me on a ride on his spaceship where I can look out the window and see I'm leaving earth's orbit--takes me on a tour of his hometown, introduces me to his family, wows me with incredible alien knowledge, buys me dinner and gets me really, really drunk....I may believe until I wake up the next morning.