"Who Did You Think I Was" was the first single released by blues-rock group John Mayer Trio from their first album, Try!. As it is from a live album, the single itself is a live recording. Speculation that Mayer was moving away from his known field of sensitive acoustic pop rock into blues was confirmed by the release of this single, being that it's a moderately heavy blues-rock song. Furthermore, the line from the first verse, "Got a brand new blues that I can't explain", indicates Mayer exploring blues unlike before.
The song also appeared as the B-side on the Trio's subsequent EP, "Live @ Yahoo! Music", after the track, "Out of My Mind", a heavily blues-influenced song written by Mayer which also appears on Try!.
The B-side to "Who Did You Think I Was" is "Come When I Call", which did not appear on the album Try!, but was frequently played throughout the trio live performances, like the song, "I Don't Need No Doctor".
Despite the single for "Who Did You Think I Was" being the version from the trio's live album, the music video of the song was a studio recording specifically for the purpose of the video itself. The music video features the trio in a worn-down factory or warehouse playing the song. In certain shots, the cameras are intentionally clearly visible to make the video have a "put-together" feel.
The guitar Mayer plays in the video is one he had custom-made by veteran graffiti and graphic artist Crash, designed and presented to Mayer in September 2006, indicating the video was shot and released after that of the Jimi Hendrix guitar that Crash based his design on.