You know what thought did

[katyb306]

why do people say 'you know what thought did' because i actually haven't got a clue what thought did!!!

[Hugh Spencer]

He thought he did but he didn't!

[Count_Emmup]

Followed a muck-cart - thought it was a wedding.

P***ed his pants - thought he was sweating.

Both earthy N/W England, (there may be more).

[VS Prasad]

"you know what thought did" is a mid C19-20 catchphrase. If one's interlocutor asks 'What?" one replies 'ran away with another man's wife.' This is a euphemistic version of the C18-mid C19 form recorded by Francis Grose, 'A Classical Dictionary of the Vulgar Tongue,' 2nd edn., 1788: 'What did thought do? Lay in bed and besh*t himself, and thought he was up'; reproof to anyone who excuses himself for any breach of positive orders, by pleading that he thought to the contrary.'
A C20 var. is recorded by Franklyn, 1968: 'The pert Cockney boy's response is, "no, 'e never! 'E only thought 'e did!"'

"what did thought do?' was a C18 catchphrase, exemplified in Jonathan Swift, 'Polite Conversation,' 1738, Dialogue I:
LADY ANSWERALL: I thought you did just now.
LORD SPARKISH: Pray, Madam, what did thought do?
The orig. form of the C19-20 'you know what thought did!' -- often extended by 'kissed another man's wife,' to quote the polite version.

http://www.phrases.org.uk/bulletin_board/13/me ssages/1490.html