I don't remember where I saw or heard this quote. It may have been from a fortune cookie, or maybe it's just a figment of my imagination. Anyways, it goes something like this.

"Being too open-minded allows everything to fall out."

“We’re not an alternative band, we’re THE alternative band.”
P-Nut bassist of 311

I thought this quip was just a one-liner bumper sticker insult type thingy, but maybe it actually is attributed to someone.

Nor is being an independent thinker and a critical thinker merely being "open-minded." As Wade and Tavris point out, "Sometimes people justify mental laziness by proudly telling you that they are 'open-minded.' 'It's good to be open-minded,' replies philosopher Jacob Needleman, 'but not so open that your brains fall out.'"
http://www.rit.org/essays/think/independent.html

The rub is finding that balance between being open-minded enough to accept radical new ideas but not so open-minded that your brains fall out.
found here

Don't be so open-minded, your brains will fall out.

Christian apologist Gregory Koukl quoted someone as saying "don't be so open-minded that your brains fall out."
~ source: "A Matter of Interpretation," 1993, Gregory Koukl, from the Christian evangelist radio show Stand to Reason
http://www.angelfire.com/ri/tucker/relativism/morality7.html

Rebecca Pippert "The enemy of our age is our desire to be tolerant and open minded. But the problem with being too open minded is that our brains fall out."
- Out of the Saltshaker, p. 90.
http://www.users.tpg.com.au/sarina21/trumpet/challengingquotes.html

A sub-category of being disciples of truth is that we are open-minded. Being too open-minded, though, has its hazards. We cannot always be just accumulating data, we have to process the information and take a stand. It has been said that if we don't stand for something, we will fall for anything. Being open-minded is not enough. It is also said that one can be so open-minded that his brains fall out.
-- Rev. Oren A. Peterson, Being a Unitarian Universalist - September 24, 2000

Then I went on to IRC, saw Eileen and Kenneth chatting. Out of curiosity again, I purposely brought the topic to homosexuality. And guess what I got. 'Tell me a good reason why they want to become homosexuals', 'its against the natural', 'the state is the result of being too open-minded'.
http://dracoism.diaryland.com/021030_21.html

One is reminded of Bloom's "The Closing of the American Mind" where he makes
the point that being too open-minded is essentially being close-minded
http://www.google.co.uk/search?q=%22Being+too+open-minded%22&hl=en&lr=&ie=UTF-8&oe=UTF-8&start=30&sa=N

"It's all very well and good to run off into the so-called real world with your eyes open looking for every squiggly nasty that you've ever wondered existed, but there is such a thing as being too open minded."
http://www.neregion.org/VSS.html


Paul warned the Corinthians about being too “open minded” –
(The Bible, 2 Cor 11:4 KJV) For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him.
http://calvarychapel.com/fullerton/Bstudy/612Pe/612Pe01-03.htm

For what will it profit a man if he gains the whole world and forfeits his soul? Or what will a man give in exchange for his soul? - The Bible, Matthew 16:26 :: NASB

The quote is widely attributed to Needleman.

"You should be open-minded but not so open-minded that your brains fall out."
~ Jacob Needleman (1987)
http://www.james-c-clark.pwp.blueyonder.co.uk/

Out of the Saltshaker & Into the World
Evangelism as a Way of Life By Rebecca Manley Pippert
Was originally published in 1979, and a revised edition published 1999. So I guess she did either stumble on the phrase first, or it could still have been a "bumper sticker" type thingy that was getting bounced around.
http://associate.com/camsoc/ots/ots-203.html
http://womeninchrist.org/bk_rvw/slt_shkr.html

An unrelated quote:

"Then, what of the American dream? Is it a vision or an illusion? Do we need to deepen this dream or awaken from it?
Can anyone doubt the importance of this question? In one form or another, it is a question that has been gathering strength for decades, and it now stands squarely in the path not only of every American, but, such is the planetary influence of America, of every man and woman in the world. What really is America? What does America mean?
To think well and truly about this question, we need to relate it to the deepest inner questions that mankind can ask."
— Jacob Needleman,
Two Dreams of America
http://www.jacobneedleman.com/