I certainly have.
Census records contradict death records, other researchers have different information on their family trees, your mom remembers that her grandpa was from Ireland, but there's a birth record from Ontario.
Many beginner researchers are surprised at the amount of uncertainty in genealogical research. Honestly, most of my genealogy is just a best guess based on the records I have been able to find. How do you make that best guess?
This article has some tips. Enjoy!