  In season one, episode 12 of The Big Bang Theory, it was left to Sheldon (played by Jim Parsons) and Leonard (Johnny Galecki) to convince the 15-year-old “highly sought after doctoral candidate” Dennis Kim (Austin Lee) to attend Caltech University to carry out his graduate work
 It didn’t take long for Sheldon and Dennis to clash, especially after the teen scientist described Sheldon’s string theory research as a “dead end”
 By the end of the CBS episode, Sheldon managed to one-up Dennis and he wasn’t to be seen or mentioned again throughout all 12 seasons of the Golden Globe-winning sitcom
 But why?What happened to Dennis Kim on Big Bang Theory? After being introduced to Leonard and Sheldon by Dr Gablehauser (Mark Harelik), the pair reluctantly showed him around the university
 When they got to Sheldon’s office, Dennis showed off his scientific prowess by discrediting Sheldon’s quantum loop corrections work
 He further annoyed Sheldon by revealing he’d won the Stevenson Award at a younger age than him
 Leonard didn’t fail to spot the similarities between the two, telling his roommate: “It’s like looking into an obnoxious little mirror isn’t it?”      Dennis’ introduction had a lasting impact on Sheldon who couldn’t get over the fact he was just 15-year-old
 Subsequently, Sheldon began exploring other avenues of his work after feeling inferior to Dennis
 This led to Sheldon pestering Leonard, Howard (Simon Helberg) and Raj (Kunal Nayyar) with their research
 The trio decided enough was enough and the only to get Sheldon to leave them alone was to take Dennis out of the picture
      The gang decided the best way to interfere with Dennis’ work was to set him up with a girl
 In doing so, they arranged a “bang your daughter to work day” during the teenager’s welcome party
 The plan initially seemed like a dead-end until a young girl by the name of Emma (Emma Segerstedt) caught Dennis’ eye
 Dennis decided to bail on his welcome party and head to the mall with his new romantic interest
 This was the beginning of the end for Dennis not just at Caltech, but in the field of science as a whole
      As the episode drew to a close, Sheldon, Leonard, Howard and Raj spotted a scruffy-looking Dennis swigging alcohol in a park
 Dennis had left the university and appeared to be living rough after being introduced to Emma
 Despite the gang being responsible for his fall from grace, an unsympathetic Sheldon said: “Screw him, he was weak
” This was the last Big Bang fans saw of Dennis and actor Lee didn’t appear in the CBS sitcom after the episode
 In fact, this was the last acting job Lee had as a whole – he appears to have turned his back on acting and Big Bang remains his last credit
   
