Posted by David FG on March 16, 2008 at 08:47:
In Reply to: Down the Clyde posted by Hal on March 15, 2008 at 09:38:
: "Do you think I came down the Clyde on a biscuit?" mean? I think it's Scottish.
Although I am not familiar with this phrase, I believe it means 'do you think I am an idiot'.
It is like the Irish phrase (with which I am familiar) 'do you think I just floated down the Liffey on a lily pad?'
The essence being that the speaker is being treated like a new-comer to the big city: as an innocent abroad.