Duck walks into a store walks up to the counter and says... I'd like to buy some duck feed.
The Clerk says we don't sell duck feed.... The Duck leaves.

The following week the Duck goes back to the same store and walks up to the counter again and says
I'd like to buy some Duck feed
The Clerk looking a bit more annoyed say we don't sell duck feed here..... The Duck again leaves.

The following week the Duck again returns to the store, he walks up to the counter and says...
I'd like to buy some Duck feed.
The Clerk says...Look, The first week you came in I told you we don't have any Duck feed.
Last week you came in I told you we don't have any Duck feed. Now, I'm telling you for the last time. We don't have any Duck feed, We never had any Duck feed
and we are NEVER going to have any Duck feed because there is no call for it.
And i'm telling you if you ever come back here again, I'm going to nail your &$%@&*$^& feet to the floor
The Duck once again leaves

The following week the Duck returns and walks up to the counter looks at the Clerk and says... Do you have any nails?
The Clerk says NO.
The Duck says, good you got any Duck feed ?