Comic book legend Stan Lee used a peculiar trick when it came to naming most of his characters over his decades in the industry: alliterative naming. Even new readers who are barely familiar with the medium have noticed the familiar pattern: Peter Parker, Reed Richards, Stephen Strange - and that's just a fraction of Lee's creations. It all arose from a very human place: namely, Stan Lee was quite a forgetful writer.
Stan Lee made a name for himself as the writer and co-creator of essentially all of Marvel's early success stories in the 1960s, including the Fantastic Four, X-Men, Daredevil, Iron Man, and many more franchises. Marvel made considerable effort to distance itself from DC Comics: the stories were set in real-world locations like New York and Chicago, there was a near-complete lack of sidekicks and super-pets, and superheroes who could lift buildings still had to worry about earthly concerns like paying rent or maintaining relationships. As Marvel's stories became more complex and interwoven, Lee adopted a unique method of naming his characters - and thus created a classic comics touchstone.
The trend began with the Fantastic Four, widely known as "Marvel's First Family" and the codifier for many of the Marvel tropes. Reed Richards and Susan Storm both have alliterative names. The Spider-Man franchise has this in spades: Peter Parker, Betty Brant, Otto Octavius and J. Jonah Jameson - and that's not even all of them. "I have the worst memory in the world," Stan Lee explained in a 2006 interview with Kevin Smith after a screening of Spider-Man 2. "So I finally figured out if I could give somebody a name where the last name and the first begin with the same letter, I could at least remember one name. And it could give me a clue what the other name was." Even the X-Men couldn't escape the avalanche of alliteration, with Scott Summers, Warren Worthington III, and Sebastian Shaw as prominent members (or enemies) of the team.
Perhaps Stan Lee was influenced by the most famous superhero in modern history: Superman. Clark Kent, while not technically alliterative, still uses the same sound if not the exact letters in both names. Oddly enough, in Just Imagine Stan Lee Creating the DC Universe (a book in which multiple DC heroes are rewritten by Stan Lee), he changed Superman's name to Salden...but invented a villain named Gundor Gorrok. In subsequent issues in the same series, Bruce Wayne was changed to Wayne Williams, and Diana Prince to Maria Mendoza.
Nowadays, an alliterative name is synonymous with the superhero genre (so much so that Wade Watson Wilson, Deadpool's name, is an outright parody of the trope). Stan Lee was right in one way: in attempting to create a system of names that he could easily remember, the system itself is now seen as a staple by many superhero fans. Considering the sheer number of character he created over the decades (well over 300), Stan Lee's allegiance to alliteration is appropriate.
Source: CBR.com