Perry, my friend, I don't mean to be rude. Since you ask me a question directly, mere courtesy alone demand that I provide you with a response. In regard to the "purely hypothetical" scenario that you have posited, the one featuring the 10-foot alien - my response is: "No, I would not believe him/her/it. What I would do is check my own meds and commit myself into the nearest...ahem...'institute'". That would be my answer.
On a side note, I ave to say - "Damn!!! A 10-foot alien!!! And I thought that they were little green men!!! That shows you how naive I am!!! Or maybe it's a giant yellow and purple polka dotted people eater? Maybe I'm getting my aliens mixed up. Never was good at extra-terrestrial taxinomy.
Well, you have a good night. It's time for this little 'un to go beddy bye.