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 ?
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.
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)
In a statement, the TTP alleged that Pakistani government hadn t responded positively to the ceasefire, which began as a monthlong observance on March 1 and eventually was extended to April 10.
Unita leader Isaias Samakuva has long criticised the electoral process, saying the voters roll hadn t been authenticated while some 2,000 of his party s observers were denied accreditation to polling stations.
Gmail, for example, wouldn t have had a fast start if Microsoft and Yahoo hadn t spent years cutting the features of their free e-mail services.
THE pressure is now on for Rangers to get their SPL push back on track after four games without a win and it is slightly surprising to see Motherwell as big as 10-1 to come away from Ibrox with the spoils tonight and virtually hadn the title to Celtic.
The reality was that the wells hadn t been drilled and therefore were not producing oil.
Former world number one Clijsters, who before this week hadn t played since March because of a right hip injury, was the champion in this pre-Wimbledon event in 2003.
In Townsville, a tropical city renowned for its easygoing lifestyle, residents said they hadn t felt a thing.
The venture however, hadn t been formerly sanctioned by ANRE.
If the West hadn t intervened there would have been a massacre," La Russa said.
Arseniy Yatsenyuk also views it unacceptable when similar situations cannot be solved at the regional level: "What would people do if they had no access to Facebook and if this question hadn t reached the Prime Minister of Ukraine?
I think there was a bit of skullduggery (sic) at the toss - Kumar Sangakkara knew he d lost that first toss but he saw Dhoni hadn t really heard him
In particular, he noted the Government had preserved a scholarship for students, hadn t raised the retirement age, left nutrition for children in 1-4 grades: "We have remained all applicable provisions of the Ukraine s law on education, including extracurricular work, and overtime work for our teachers, which is payable in accordance with the law".