Phr.: to come up the Clyde on a banana boat; variants to come up the Clyde on a bike, to come up the Clyde on a wheelbarrow, to come up the Clyde on a banana skin. Phrs. used, usu. in neg., as an indication of stupidity or naïvety (Bnff., Fif., Edb., Ayr., Dmf., Rxb. 2000s).

He writes: “There is a saying in Glasgow: ‘Do you think that I came up the Clyde on a banana boat?’ “It is most often said in response to the telling of an incredible story, or after someone tries to pull a trick on another, but is found out. A humorous way, typically Glaswegian, of saying: ‘Do you think I’m stupid?’