Trivia: In the Marvel Comic series where the characters originate from, Deacon Frost was actually an elder man, and an alchemist who dabbled in vampirism and - via one of his experiments - turned himself into a unique vampire who could create doppelgangers of his victims.
Trivia: This film, along with 2000's "X-Men" and 2002's "Spider-Man," are often cited as the three movies that helped revive the comic-book-movie genre after several poorly-received 90's movies like "Batman and Robin" and "Steel" had effectively killed it for a few years.
Trivia: The original Marvel Comics' Blade was a member of a band of vampire hunters, who mainly fought Dracula (who also was a regular at Marvel). The others included Quincy Harker and Rachel van Helsing (both descendents of Dracula's enemies from Bram Stoker's novel), and Hannibal King (a vampire detective, and a victim of the original Deacon Frost).
Trivia: During the chase with officer Krieger, the vampire on the side of the road biting the girl's neck is actually director Stephen Norrington. (00:40:15)
Trivia: Blade's tattoos were designed by director Stephen Norrington.
Trivia: The film came about in-part due to the fact Wesley Snipes wanted to star in a Marvel superhero movie, but his dream project - "Black Panther" - got stuck in development Hell. Eventually, Snipes became intrigued by the Blade character, and helped get the film made. A "Black Panther" film was eventually made (without Snipes), and released exactly twenty years after "Blade" hit screens.
Trivia: The visual effects in the subway scene were cutting edge at the time, and the visual effects artist working on the sequence had to match the digitally-created trains to the film frame-by-frame due to the camera movement and jitter. You can briefly see people inside of the trains as they pass by, which were just still images of people standing, since they went by so quick you could barely see them. One final amusing note about the scene: In the making of, the digital effects artist mentions that one day, he hoped the software would exist so that motion and camera movement could be digitally tracked so digital elements wouldn't need to be matched in frame-by-frame. This idea (motion tracking) is now - 20 years later - such a common effect technique that it's available in most animation software (including many free and/or cheap programs) as a very basic feature.
Trivia: Blade's somewhat infamous one-liner "Some mother****ers are always trying to ice-skate uphill" was something that star Wesley Snipes once casually said in conversation while trying to describe the character of Deacon Frost. Director Stephen Norrington and writer David S. Goyer thought it was such a bizarrely unique expression, they vowed to work it into the script somehow.
Trivia: Donal Logue, who plays Quinn, fell and dislocated his jaw during the filming of the hospital scene, where his severely-burned character attacks Karen. He had to be rushed to a real hospital while still in full burn makeup, which caused a panic among the staff, as they thought he had really been severely burned over his entire body.
Trivia: At Deacon's place, the vampires are watching Mortal Kombat, also made by New Line Cinema.
Trivia: The character of Whistler was created by writer David S. Goyer for this film, but first debuted in the Spider-Man animated series TV show.
Trivia: Whistler was named Abraham as reference to Abraham Van Helsing, the vampire slayer in Dracula's novel.
Trivia: Mark Wahlberg, Skeet Ulrich and Bruce Payne were considered for the role of Deacon Frost.
Trivia: Jet Li rejected the role of Deacon Frost because he was involved in Lethal Weapon 4.
Trivia: Denzel Washington and Laurence Fishburne were considered for the main role.
Answer: I don't think it's so much a memory as it is Blade just equating Karen with his mother in that moment. The only way to convey his thought process to the audience, though, is to show his mother onscreen.
Phaneron