Sheldon: You participate in the mass cultural delusion that the sun's apparent position relative to arbitrarily defined constellations at the time of your birth somehow effects your personality.
Sheldon: I'm not crazy. My mother had me tested.
Sheldon: You have about as much chance of going out with Penny as the Hubble Telescope has of finding that at the center of each black hole there's a little man with a flashlight trying to find the circuit breaker.
Penny: Can you help me? I was writing an email and the A key got stuck. Now it's just going "Aaaaaaa."
Sheldon: Coffee is out of the question. When I moved to California, I promised my mother that I wouldn't start doing drugs.
Sheldon: Oh, well, this would be one of those circumstances that people unfamiliar with the law of large numbers would call a coincidence.
Suggested correction: Not being able to afford doesn't necessarily mean he doesn't have the money, especially a man like Sheldon. He works with a budget and he sticks to it. In his budget he has a certain amount set aside for rent, anything more than that and he can't afford it alone.
Nonsense. If he was sticking to a "rigid budget" he wouldn't have even thought of lending a hopeless credit risk like Penny a single cent. Instead he throws a huge bankroll at her without even discussing a repayment plan.
Rubbish, I stick to a strict budget but still have the money to lend to close friends. Like Penny is to him.
He might have different budgets for different things. People could get a higher margin because they could be of more use to the scientific mind of Sheldon.