Here are some of my favorite quotes about QM
(don't let them discourage you though! They're just worrying about philosophy :-)

    * Everything we call real is made of things that cannot be regarded as real. Niels Bohr.
    * Those who are not shocked when they first come across quantum theory cannot possibly have understood it. Niels Bohr.
    * If you are not completely confused by quantum mechanics, you do not understand it. John Wheeler.
    * If [quantum theory] is correct, it signifies the end of physics as a science. Albert Einstein.
    * I do not like [quantum mechanics], and I am sorry I ever had anything to do with it. Erwin Schrödinger.
    * Quantum mechanics makes absolutely no sense. Roger Penrose. 
    * It is safe to say that nobody understands quantum mechanics. Richard Feynman.

And, in a little more detail, from Richard Feynman:

I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possibly avoid it, ‘but how can it be like that?’ because you will get ‘down the drain,’ into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that.

Richard Feynman - The Character of Physical Law (Lecture 6)

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Here's a rather more optimistic quote:

“In two slit interference, quantum mechanics cannot determine which slit the electron went through.”
This statement reflects not the poverty of quantum mechanics, but its richness.
In classical mechanics, an electron must have a position — it must pass through one slit or the other.
In quantum mechanics an electron might have a position, but there is an infinitely rich variety of other possibilities as well.

It is no failure of our instruments that they cannot measure what does not exist.

The English language was invented by people who didn’t understand quantum mechanics, so it is unsur-
prising that the language lacks a concise, accurate description of many quantal phenomena.
The strangeness of quantum mechanics carries us to the brink of implausibility — but not beyond.

- Dan Styer, http://www.oberlin.edu/physics/dstyer/TeachQM/

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And below are two student poems, from a sweet little book called "Dear Professor, Do you Live in a Vacuum" a collection based on emails sent to a physics professor and compiled by his wife.

You asked if I listened in class today.
And I am writing you now
to show you that I did listen.
You said that if the uncertainy of one is zero,
then the uncertainy of the other is infinite.
It's just that you're one,
and I'm the other one.

In describing a photon,
you said that a photon is not a wave,
and it's not not a wave.
And I'm saying that I'm not with you,
and I'm not not with you.