He had a spreadsheet -- called girls.xls -- where he kept track of important details about each woman he went on a date with.
We were sitting around musing about how hard it must be to keep track of the key details given all the dates he was going on, and he let drop that he had a spreadsheet.
He never showed it to anybody and it didn't sound creepy - it was genuinely a tool he used in good faith given the volume of info he was trying to keep track of.
And, he ended up marrying #42.