One of the problems with Genealogy is how names changed as you go back in time. Not so long ago, many people wrote phonetically and cared nothing about correct spelling, so you might find the same person's name spelled several different ways. The other finding is that many old official records (census, birth and death, marriage, wills, etc.) produced before typewriters existed were hand-written, and are often nearly indecipherable. So when such records are used to trace lineage, whoever transcribed them could easily have made serious mistakes. Many times, I have reached the point where the family tree stops cold because I can't determine a name with certainty. Another problem is too many common names. Say, if you knew for sure that your GGGMs name was Mary Smith and you knew she lived in New York City in the mid 1800s, you are going to find dozens, if not hundreds, of Mary Smiths were there at that time, with no clue which one of them (if any) was your GGGM. I ran into that situation with one of my GMs. I knew her name and her parents' names, that they lived in Cincinnati in the mid-19th century, and that both parents came from Germany, but their names were so common that I was unable to get any additional information beyond that. It didn't help that at around that time almost everyone in Cincinnati seemed to have come from Germany. So that branch of the family tree has stopped there, at least for the present.