And the other one that doesn't help is people going by their middle names - Dad was having trouble finding the line descending from his grandmother's son from his first marriage, under what he'd been told was the name he went by. (From what I understand, he knew my grandad's other siblings but not that one - he was surprised the day my aunt told him Grandad had this half brother, and that was something like 2014, but then remembered an incident from his teens where he'd been talking to his grandmother about some girl he'd met at a party while playing Spin the Bottle, and his grandmother had said "That's your cousin".) When he was trying to do the family tree, he looked into that branch but the Palfreyman branch of the family seemed to have vanished into thin air, and he put that down to his uncle going by a middle name.