“They are so busy knocking that they do not notice that the door is open!”

“Jools Holland: "Knock Knock!"
Morrissey: "I'm not in!"
Jools: "Oh, come on."
Morrissey: "I refuse to open the door."”

“When I knocked, the door opened. When I looked, I found.”

“When you try to generate ideas, think of yourself as a sales person knocking on a whole subdivision of doors. Some won't open at all, some will open a suspicious crack, and some will slam in your face. But the more doors you knock on, the greater your chances of being invited in.”

“You knock at the door of Reality. You shake your thought wings, loosen your shoulders, and open.”

“Don't simply knock and wait for the door to be opened. Go look for the keys. Some fit the lock better than others.”

“There was no warning, not even a knock. The door flew open, and he forgot his present aches and pains in anticipation of what lay in store. The figure that stood in the door was not that of an enemy. It was worse. It was his mother.”

“Most people are so busy knocking themselves out trying to do everything they think they should do, the never get around to doing what they want to do.”

“When one door of happiness closes, another opens; but often we look so long at the closed door that we do not see the one which has been opened for us.”

“We're knocking on the door of success.”