If you want to be remembered, hum them a song. Should there come a time when they have forgotten details of your moments together, trust that they will remember you with that song.
They may be quietly reading some cerebral book while sipping a creamy blend of iced latte in a mall cafe nook out of town totally lost in the book`s message in the foreground while stressing about some ongoing dilemma in the background before the song suddenly plays. That ought to give them a start.
If they were me, they would look up from their book in recognition of the slow warmth emanating from their stomach to their chest just like how kids react when they hear the tune of their favorite ice cream truck.
As this fondly remembered song plays, they will laugh rather loudly while listening to the lyrics. They will remember the person that they were then, probably someone naive and idealistic, and then they will laugh again. At that exact moment, the song will interrupt their train of thoughts, singing, “Cinderella said to Snow White `How does love get so off course?`” They will then wonder why certain parts of the song stick more than others. Why do some memories stick more than others?
At this moment, know that they will remember you. Before they drink all of their coffee and walk out into the dazzling light outside, they will pause to wait for their favorite part to play before they walk outside, singing.
That exact moment you allowed them to enjoy, that bit of nostalgia your song caused, imagine that exponentially multiplying into the various lives you have touched. Now that is your legacy.
Always make it a good song.