what does this pharse mean?
【'I thought there was supposed to be a recession,' said Bruno. He was looking around at all the packed tables.
'Penny hasn't dropped yet,' said Addie.
'Penny dropped for me a while ago.'
'Is that why you came? Because you lost your job?'
'That,' he said, 'and the election. I was getting upset about the election, I needed some perspective. So I told myself, book a round trip, Bruno. Book a round trip, come back when it's over. If Obama wins, I can make a triumphant return. If McCain wins . . . ' He leaned in over the table for extra emphasis. 'If he wins, I'm tearing up my return ticket. If he wins, I'll eat my ticket.'
She laughed, that bubbly laugh that burst out of her with no warning. But silently she was thinking, that's less than a month away.】

what does "'Penny hasn't dropped yet" mean? thx~

Question

what does this pharse mean?
【'I thought there was supposed to be a recession,' said Bruno. He was looking around at all the packed tables.
'Penny hasn't dropped yet,' said Addie.
'Penny dropped for me a while ago.'
'Is that why you came? Because you lost your job?'
'That,' he said, 'and the election. I was getting upset about the election, I needed some perspective. So I told myself, book a round trip, Bruno. Book a round trip, come back when it's over. If Obama wins, I can make a triumphant return. If McCain wins . . . ' He leaned in over the table for extra emphasis. 'If he wins, I'm tearing up my return ticket. If he wins, I'll eat my ticket.'
She laughed, that bubbly laugh that burst out of her with no warning. But silently she was thinking, that's less than a month away.】


what does "'Penny hasn't dropped yet" mean? thx~

Answer

The penny drops when you see the true situation.  If you get the punch line to a joke, the penny dropped.
It is usually applied in a situation where a person did not realize something was happening or the hidden meaning of some sentence..  If they still are not aware of it, the penny hasn't dropped.
"It looks like I've got a lot of free time on my hands now, with really flexible working hours."
"You mean you were fired?"
"Oh, I see the penny dropped."

The phrase comes from the old penny slot machines that sold candy.  You wouldn't get the candy until the penny had dropped completely into the machine.