2 + 2 = 5

2+2=5 comes from the book "1984", where the Government had so deeply trained society to instantly, without thought, accept any official statement as true and instantly erase the past (2+2=4). Harkens to the Marxist belief that the State is the ultimate truth and individuals with an alternate "truth" are dissidents. Some employers and leaders also fall into this belief that reality is nothing but paradigms despite empiric facts offered by "not a team player" people.

A reference to 1984; signifies somebody has been completly whipped/controled to the point that the person believes/will do anything the whipee/controler tells them. Usually used to mock a friend who has decided to pass up a night with the friends to go do something incredibly gay with their signifcant other.

It's also the title to a radiohead song

Part of the Book "1984", It shows how Big Brother has brainwashed the people so much that they belive 2+2=5.

A joke that nerds usually make about the rounding of numbers. If you do 2.3 rounded (2) + 2.4 rounded (2), you get 4.7 which rounds to 5.

And because humans are imperfect, we are never able to make exact precision on anything. This means, that anything we do, we are doing some kind of rounding/estimation at some point. So, this means that 2 + 2 = 5 but only for very large values of 2.

a track from radioheads "hail to the thief" amazon.com have reviewed the album they said:

"Hail to the Thief borrows equally from each. Its title implies that this will be a collection filled with songs of anger and dissent, but Radiohead no longer howl at the moon like they did on 1995's The Bends. Instead, they use eloquent metaphors and complicated arrangements to express the uncertainty, fear and anger arising from the 2000 U.S. presidential election and a post-9/11 world. There’s no doubt about where Thom Yorke and company stand; the prog-rock break on "2 + 2 = 5" and Yorke's terror at the thought of being "put in a dock" make that immediately clear"

it can be used to express strange things that have happend , and or lack any sence

Interesting fact: 2.4 (which rounds to 2) plus 2.3 (which rounds to 2) is equal to 4.7 (which rounds to 5).

Maths nerds making a joke out of some line from George Orwell's 1984