The actor who plays a fictionalized version of himself on the show is Wil Wheaton. Wheaton appears as a heightened, comedic version of his public persona on The Big Bang Theory, where he becomes a recurring guest character and one of Sheldon Cooper’s early enemies.
Sheldon originally idolized Wheaton because he played Wesley Crusher on Star Trek: The Next Generation. Sheldon’s feelings change after Wheaton fails to appear at a convention Sheldon traveled a long way to attend. Sheldon treats the incident as a personal betrayal and places Wheaton on his list of mortal enemies. The two eventually repair their relationship, although later conflicts briefly revive their rivalry.
Wheaton’s role is fictionalized rather than a straightforward documentary portrayal. The real actor also appeared in Stand by Me and Toy Soldiers and became closely associated with science-fiction fandom through Star Trek. Other Star Trek performers, including LeVar Burton and Brent Spiner, also guest-starred on The Big Bang Theory, but they did not fill the same recurring fictionalized-self role.