Posted by Smokey Stover on July 09, 2006
In Reply to: "You're all wet" posted by Ward on July 08, 2006
: The archive does not cover the origion of the expression "you're all wet"
: It means you are wrong, but when did being wet mean the same as being wrong?
Your question was "when." The closest I can come is what the OED tells me.
"c. all wet: mistaken, completely wrong. orig. and chiefly U.S.
1923 N.Y. Times 9 Sept. VII. 2/1 All wet, all wrong. 1931 Kansas City Times 29 Aug., Alfalfa Bill Murray may be 'all wet' in his state-line bridge and oil production controversies. 1940 G. ADE Let. 5 June 221 Regarding the Rotary Clubs, I..am an honorary member. I think the organization is alright and that Sinclair Lewis was all wet when he tried to poke fun at the small town booster. 1941 E. B. WHITE Let. Summer 216, I haven't had much time to think things over and I am probably all wet on a lot of things in here. 1951 A. BARON Rosie Hogarth 282 You're all wet if you think I'm giving up that easy."
"Wet" in a derogatory sense is a bit older, but only a bit. Let's try the OED again.
"b. Inept, ineffectual, effete; also as quasi-adv. and in comb. wet fish, a wet individual, a 'drip'. Also spec. in Politics (see quots. 1981 and 1983). Cf. WET n.1 6.
1916 'TAFFRAIL' Pincher Martin ii. 27 I'll give yer a clip 'longside the ear'ole if you ain't careful. Don't act so wet. 1924 P. MARKS Plastic Age 94 They attended a performance of Shaw's 'Candida' given by the Dramatic Society and voted it a 'wet' show. Ibid. 192 A man is wet if he isn't a 'regular guy'; he is wet if he isn't 'smooth'; he is wet if he has intellectual interests..; and he is wet..if he is utterly stupid. 1938 E. BOWEN Death of Heart II. iv. 239 Cecil is so wet! Coming early like that, then sticking round like that. 1944 A. CHRISTIE Towards Zero 86 Audrey marry that wet fish? She's a lot too good for that. 1963 Wet fish [see MOOSE1 c]. 1969 K. AMIS Green Man iv. 180 The Jesus of the Gospels can be a bit of a wet liberal at times. 1973 P. O'DONNELL Silver Mistress iv. 74 Don't talk wet, Jan. There's nothing you could do. 1980 Times Lit. Suppl. 28 Nov. 1355/2 The contrast between the splendid façade and the rather wet interior of the man [sc. Havelock Ellis], who was kind and gentle and distinguished, but also distressingly absent, indifferent and faint.
1981 Observer 26 July 12/3 The term 'Wet' was originally used by Mrs Thatcher, who meant it in the old sense of 'soppy', as in 'What do you mean the unions won't like it, Jim? Don't be so wet.' It meant feeble, liable to take the easy option, lacking intellectual and political hardness. Like so many insults, it was gleefully adopted by its victims, and so came by its present meaning of liberal, leftish, anti-ideological. 1982 Listener 23/30 Dec. 6/3 In considering the promotion of wet (or wettish) Ministers, she will tell herself that Pope was right. 1983 Age (Melbourne) 5 Oct. 13 Britain's Tory Prime Minister, Mrs Margaret Thatcher, began this vogue terminology by contemptously dismissing dewy-eyed dissenters from her arid Right-wing policies as 'wet'."
You have noticed, I'm sure that "all wet" is an Americanism, and that the Brits are more inclined to describe things they don't admire as "wet."