oh... so many things...
I thought that the time stamps meant that it was all real time-- i thought somewhere in the world they were months ahead/behind.....
I also thought dragons were real because History channel had this guy saying they were, and that the babies are alive on the mountains somewhere or something [this was when they started becoming a channel with conspiracy and reality shows]
Also thought Toy Story was real.
Also thought germs stay in an area for years so there was one spot i avoided walking into because i saw someone sneeze there.
thats all I can think of for now.