Mário, esta é para ti

PENNY

“Maybe it's all for the best. I always say when one door closes, another one opens.”

SHELDON

“No, it doesn't. Not unless the two doors are connected by relays or there are motion sensors involved.”

PENNY

“No, I meant...”

SHELDON

“Or if the first door closing creates a change of air pressure that acts upon the second door.”

PENNY
“Never mind.”