Whenever I identify someone, whether they be fictional or real, it's because I noticed a unique trait of their character. But whether or not I'm able to notice it depends on how well the author reveals parts of the character. How the author chooses to expose a character's traits can rely on where the character lives, how he was raised, who he encounters, etc. All these things have an impact on how a person acts and how it shapes his identity.
"My momma always said 'life was like a box of chocolates. You never know what you're gonna get.'"
Symbolism is always a great way to enhance a character's identity. Whenever you hear the name "Forest Gump" do you not automatically think of a box of chocolates? This symbolism hepls us to identify the unpredictable life of Forest Gump.
One other way that helps the audience to remember a character is putting them in a similiar situation the audience can relate to. Picture the scene in the short story "Brother Dear" where Sharlene was caught in the middle of a heated arguement between her brother and her father. There was nothing she could of said or done to help resolve the matter. I'm sure everyone that has experienced family drama can remember a time where they felt just as helpless as Sharlene in that particular situation.
Without giving anything to make a character stand out, readers/viewers tend to turn a blind eye to supposedly key factors of the author's character and may dismiss them as just a cameo or 'background' for the plot. It is essential for any author to use these strategies if they intend to make their characters relics of something to be remembered.
