if it hadn't been for (someone or something)

If someone or something hadn't helped, intervened, or affected the situation in some way. The phrase is always followed by an explanation of how things would have turned out differently without someone or something. If it hadn't been for those quick-thinking bystanders, I wouldn't be alive today. If it hadn't been for those meddling kids, we would have gotten away with it.
See also: been, if

have not heard the half of it

To know only a small part of how bad something is, but without understanding the complete situation; to underestimate or be uninformed about how bad a situation really is. Our bosses think that this is a major setback, but they haven't heard the half of it. We're months, not weeks, behind schedule! A: "I heard you and Terry were going through a tough time." B: "Oh, you haven't heard the half of it."
See also: half, have, hear, not, of

not know enough to come in out of the rain

To not have very much intelligence or common sense, especially when facing or presented with a difficult situation. I'm not surprised his latest business venture failed too—that fool doesn't know enough to come in out of the rain. Cut him some slack, Jim. You didn't know enough to come in out of the rain when you were his age, either.
See also: come, enough, know, not, of, out, rain

hadn't oughta

Inf. should not have. You hadn't oughta teased me like that. I know I hadn't oughta stolen that candy.

not know enough to come in out of the rain

Fig. to be very stupid. Bob is so stupid he doesn't know enough to come in out of the rain. You can't expect very much from somebody who doesn't know enough to come in out of the rain.
See also: come, enough, know, not, of, out, rain
References in classic literature ?
"Dat bloke was a dandy," said Pete, in conclusion, "but he hadn' oughta made no trouble.
It hadn't ever come home to me before, what this thing was that I was doing.
"Pooty soon I'll be a-shout'n' for joy, en I'll say, it's all on accounts o' Huck; I's a free man, en I couldn't ever ben free ef it hadn' ben for Huck; Huck done it.
I tried for a second or two to brace up and out with it, but I warn't man enough -- hadn't the spunk of a rabbit.
'I'm sooary I ha spok'n on 't,' said Stephen, 'I ought t' hadn in my mind as I might touch a sore place.
One netizen wondered if Prince Charles would have still married Camilla even if Princess Diana were still alive and hadn't lost her title.
Party Chairman Bilawal Bhutto Zardari has stated that PPP had faced dictatorship and terrorism but hadn? taken any U-turns like PTI.He stated this while addressing a function of Sindhi Cultural Day.
In 2011, the ex-Foreign Minister joined PTI but parted ways during 2013 reasoning that Imran Khan hadn t kept the promise with him.
Tenders are invited for Drilling Of Borewells And Providing And Fixing Hadn Pumps At Various Locations Khadki Cantonment (Out Of Cantonment Funds) (Iv Call)
It does feel a little bit weird now because it was such a long time ago, but it's quite strange that before doing Blind Date I hadn''t really expressed an interest in television, I'd never actually thought it was something that could feasibly happen.
2008 League Cup Final - Everton 1-0 Arsenal THE Gunners hadn''t been beaten domestically in almost two years and few had given the Blues hope.
I''ve memories of drinking ridiculous volumes of ridiculous drinks in ridiculous ways (snorting vodka anyone?) or would have if I hadn''t done it.
7 What did the Barbie Doll get in 2000, which it hadn''t had before?
If only I hadn''t written on my hand and slept on it.
And while Tina is forced to bond with him in ways she hadn''t expected, she''s also getting closer to Tommy again as well.