Flattybasher's advice would amuse many of us. But we have all been there. Prior to easier on-line access I thought for years that a greatgrandfather and ggmother lived on one street, and wondered about children of theirs I'd never heard of, based on family information.
Online, I probed further because there were bits that puzzled me. There were two men with the same first names and surnames, the same name for the wife, and three names of children in common. They lived in the same town, close together. All ages were close enough to be relevant, but THE RIGHT ONE WAS THE OTHER ONE, not the railwayman that I'd been provided with, but the joiner a few streets away!! I'd been chasing the wrong family for the wife, ( I've only recently got her pinned down, but beautifully) having the wrong surname from the wrong marriage ... thank goodness something rang an alarm bell, and I took it all apart, and found the right reference material in the end. It taught me not to take ANYTHING on trust without checking, checking, checking, - and I do usually chart out the "elimination by comparison over the years" to help me keep it all clearly in my mind. Thank heavens for A2 sheets of paper, and l-o-n-g rulers!