It is important somewhere to keep track of your research logic as you progress. Otherwise you might not remember “why” you are researching a certain person.
While at the Allen County Public Library last August, I focused on a certain Benjamin Butler in 1850 as being “mine.” Using that enumeration as the starting point, I searched other records and made research progress. A stack of papers and records. One problem–I didn’t track WHY I thought this 1850 census entry was for the correct person. It took me hours to reconstruct my reason. Time wasted when I started writing up the 1850 Benjamin for an issue of Casefile Clues.
When I decided the 1850 guy was “mine,” I should have written down my reasons. That would have saved time.