Comment by Felix Ronkainen (felix-ronkainen) on Sherlockian Abduction Master List · 2024-07-18T16:01:17.400Z · LW · GW

A tatoo or jewelry of an astrological sign is a pretty strong indication that their birthday falls within the associated dates.

Also, Conan Doyle based Sherlock Holmes off of one of his university professors, who he claimed had the same observational abilities as Holmes.