La serie, ambientata a Pasadena, in California, racconta le vicende di quattro giovani scienziati, Leonard, Sheldon, Raj, e Howard, che lavorano insieme al California Insitute of Technology e che fanno amicizia con Penny, una bellissima ragazza venuta a vivere nell’appartamento di fronte a quello condiviso da Leonoard e Sheldon..
Quando Leonard si innamora di Penny, lo strano mondo dei quattro amici, nerd a tutti gli effetti (molto intelligenti, amanti di fumetti, videogiochi, fantascienza), si scontra con quello semplice e superficiale di lei.
Sheldon: A little misunderstanding? Galileo and the Pope had a little misunderstanding…
Sheldon: Why are you crying?
Penny: Because I’m stupid!
Sheldon: That’s no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and that makes me sad.
Sheldon: Biologically speaking, Howard is perfectly justified in seeking out the optimum mate for the propagation of his genetic line.
Wolowitz: Thank you, Sheldon.
Sheldon: And whether that propagation is in the interest of humanity is, of course, an entirely different question.
Sheldon: What part of an inverse tangent approaching an asymptote don’t you understand?
Sheldon: I grew up in Texas. Football is ubiquitous in Texas. Pro football, college football, high school football, pee wee football… in fact, every form of football except the original, European football, which most Texans believe to be a commie plot.
Leonard: You are not Isaac Newton.
Sheldon: No, no, that’s true. Gravity would have been apparent to me without the apple.



