1. There is no "A" in Cemetery.
2. The census takers, more often than not, didn't really care when your relative was born, or how your relative's name was spelled. They spelled it like it sounded. They also didn't really care if the two year old hanging off of the Polish woman they were questioning was a boy or a girl, and they couldn't understand Polish anyway. Thats why your great uncle is a girl in 1900 and a boy in 1912. Its still the same person.
3. There are occasionally errors in original records. There are quite often errors in transcriptions. The guy transcribing the 1880 census didn't realize that your great grandmother was really a proselytine (a missionary), and wasn't actually a prostitute. Sorry about that.
4. Just because it was printed in a book, doesn't make it true.
5. Just because it was posted on the internet, doesn't make it true.
6. Just because someone else downloaded it and re-posted it still doesn't make it true. If they can't get your grandfather married to the right woman, most likely the lineage to Joan of Arc isn't quite true either.
7. "newspaper clipping" is not enough information for a proper source citation. Neither is "Aunt Mable".
8. Buying every subscription to every online website will not guarantee you find your grandfather. (Steven Morse found your grandpa in "one step", though - http://stevenmorse.com/grandfather/index.html)
9. Doing all of your research online is like licking your fork and calling that dinner. Go to the library! the courthouse! the cemetery! Write some letters! Call some relatives! Dare I say it... turn off your computer! (ok, but only for a little while)
10. Only another genealogist will be interested enough to listen to the story of your ancestry back to Charlemagne. But you have to be willing to listen to theirs too. He's my 35th great grandfather, by the way ;)