On October 9, 2007, a full-length (1 minute and 45 seconds) version of the song was released commercially. Although some unofficial pages identify the song title as "History of Everything," the cover art for the single identifies the title as "Big Bang Theory Theme." A music video also was released via special features on The Complete Fourth Season DVD and Blu-ray set. The theme was included on the band's greatest hits album, Hits from Yesterday & the Day Before, released on September 27, 2011. In September 2015, TMZ uncovered court documents showing that Steven Page sued former bandmate Robertson over the song, alleging that he was promised 20% of the proceeds, but that Robertson has kept that money entirely for himself.
After Sheldon reminds the guys about the time they mined Bitcoin without him, the guys go on a quest to find their suddenly valuable missing cryptocurrency. They realize the currency is on a laptop which Leonard gave to Penny when they dating, which she then gave to her ex-boyfriend Zack. After Leonard and Penny go to Zack's apartment, he shows them a seven-year-old video that Penny recorded on the laptop soon after she broke up with Leonard. Leonard is touched by the video which shows a drunk Penny lamenting the break-up of her relationship with him.