Occam's Apartment

Your dear friend Detective William Occam recently passed away while investigating a case about a 10-year-old missing girl, Nina. Following his death, you received a mysterious letter.
Addressed to his closest friends, a single message was left behind: “There are two sides to every man, the one that you see and the one hidden behind the scenes. I can only be the real me when I go fishing on the lake. Memories I will never forget.”