I suppose most folks know where this comes from but for those that don't, here's a bit of history. Julius Ceaser invented the Julian calender in 46 BC + the beginning of the year was April 1st. In the mid 1500s Pope Gregory replaced it with the Gegorian calendar ( which we still use) with the beginning of the year as Jan. 1st. When this new calendar was 1st introduced there were many who refused to change + those were dubbed 'fools'. Thus anyone using the Julian system was a fool + the legend started, with variations.