'Young Sheldon' Reveals Origins of Sheldon's 'Soft Kitty' Song

Young Sheldon made a big reveal during Thursday's all new episode.

The show, which tells the story of young Sheldon Cooper (Iain Armitage) growing up in Texas, told the story behind "Soft Kitty" the song adult Sheldon (Jim Parsons) has to hear every time he is sick.

In the episode, titled “A Sneeze, Detention, and Sissy Spacek” according to Variety, flu season hit Medford and the titular young Sheldon did whatever he could to try to avoid getting sick, including putting on his astronaut Halloween costume (complete with helmet!) — but unfortunately his efforts did not prove to be enough.

Too sick to move around, Sheldon laid in bed with a compress on his forehead as his mom (Zoe Perry) sang to him. After hearing the verse once, Sheldon smiled and asked for it again — the beginning of something that becomes a pattern for him that follows him to adulthood.

Fans of the Big Bang Theory spinoff took to Twitter to celebrate the debut of their favorite song from the mothership series on Young Sheldon.

According to Variety, Young Sheldon — executive produced by Chuck Lorre, Steve Molaro, Jim Parsons and Todd Spiewak — is the No. 1 new comedy in viewers, adults 18-49 and adults 25-54 and the No. 2 comedy in all of television, behind its predecessor The Big Bang Theory. The most recent episode saw 14.17 live+same day total viewers and 2.6 in the 18-49 demo.

The show has already been renewed for a second season. The show airs Thursdays at 8:30 p.m. on CBS.