We don't think Simon Cowell has had a surprise like this since Susan Boyle walked out on the Britain's Got Talent stage. 

82 year old John Hetlinger, a former Navy pilot who had also worked on the Hubble telescope. When asked why he wanted to come on the show, Hetlinger answered that getting the opportunity to perform on the show was the high point of his many distinguished careers. 

Cowell and his fellow judges were so charmed at this response that they must have been a severe bolt out of the blue when they learned the song that Hetlinger chose to cover - Drowning Pool's 'Bodies'.

Despite the initial shock from the audience, it wasn't long before they were all on their feet and banging their heads in approval.
 
While Hetlinger is unlikely to enjoy the same post show success as Susan Boyle we hope this moment is remembered because he's a true hero in our book. 
 
Via Uproxx