“If an opportunity does not knock why not build a door?”
“If opportunity doesn't knock, build a door”
“If opportunity doesn't knock your door,then build a new one.”
“When opportunity doesn't knock, create a door”
“Opportunity may knock once, but temptation bangs on your front door forever.”
“Knock and it shall be opened.' But does knocking mean hammering and kicking the door like a maniac?”