Penny does care for Sheldon during illness or Penny takes him in when he is locked out of his apartment while his friends are in Las Vegas. When Amy toasts Sheldon she remarks that it is traditional that the birthday boy get the presents, but her greatest present ever was the day he was born. Sheldon regularly reproaches Penny and other people for sitting in his spot. After Bernadette finally gave birth, Sheldon and Amy went to the Harry Potter theme park together and returned to the bedroom to complete Amy's birthday celebration. "Basic math simply won't allow it", as Sheldon puts it. He has stated in an interview that he is a bit of a germaphobe and washes his hands a lot but doesn't always use lotion which is why his hands are red. Sheldon's IQ of 187 points places him in a very small fraction of a percent of the most intelligent people in the world. Amy suggested they spend the night building a fort in the living. Amy invites Leonard to a wedding, explaining that she'd invited Sheldon before, but he "acted like a child." Misleading thumbnail is misleading. In "The Friendship Contraction", Sheldon asked Amy to take him to the dentist after all of his other friends refused after Leonard had signed the clause on The Roommate Agreement to reduce his and Sheldon's relationship to mere acquaintances. Although Sheldon greatly appreciates the love and support she gives him, he's uncomfortable with her religious beliefs. Though it was meant to be quick and sarcastic, Sheldon seems to enjoy it and lingers. Sheldon soon realized he made a mistake and was uncomfortable being praised for his accidental discovery. A second piece is in front of the toilet "for those that stand up to pee", though what exactly it marks was not specified. Amy is flattered and smiles. At the beginning, she even made a suggestion, which Sheldon described as brilliant (highly unusual, since he normally dismisses other people's comments about his work though he is willing to listen to her). An IQ score is a normalized, scaled representation of the percentage of people that are at least as "intelligent" (as measured by the test) as the scored person.
Amy excuses herself and Dave gets excited about meeting him, then she tells Sheldon that it's not a good time.
He is also worried over them becoming step-brothers if their father and mother get married. Howard, Leonard and Sheldon met with the Air Force representative to discuss their guidance system, Sheldon landed the guys with a harsh deadline.
In "The Conjugal Conjecture", Beverly actually snaps at Sheldon when he acts crazy after hearing that her ex-husband is probably hooking up with Sheldon's mother, her maternal rival and then Sheldon actually talks back to Beverly taking offense of her calling his mother a Bible thumping bumpkin though he admits her analysis is partially correct.