“… if you don’t want your tax dollars to help the poor, then stop saying you want a country based on Christian values. Because you don’t.” - John Fugelsang
No, not Jimmy Carter. Jimmy Carter on Helping the Poor | Snopes.com
The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka!”, but “That’s funny…” --Isaac Asimov
When I googled to find out the exact wording, guess which message board and which poster came up as the top result. 
David Foster Wallace.
A universe simple enough to be understood is too simple to produce a mind capable of understanding it. (Cambridge cosmologist John Barrow)
“A woman hopes that the man she loves will change. A man hopes the woman he loves will never change. Both are invariably disappointed.”
-attributed to all the usual suspects from Oscar Wilde to Mark Twain to Winston Churchill… but I haven’t found any documentation that any of them ever said anything like this.
“Nope. I wish it wasn’t raining.” Unknown mechanic to a young Jerry Seinfeld, who asked if the downpour he’d ridden through made him wish he’d bought a car.
“I must not fear. Fear is the mind-killer. Fear is the little-death that brings total obliteration. I will face my fear. I will permit it to pass over me and through me. And when it has gone past I will turn the inner eye to see its path. Where the fear has gone there will be nothing. Only I will remain.” - Frank Herbert
“Don’t think 'cus I understand, I care” - Sneaker Pimps
A man don’t know how big a shadow he’ll throw til he stands up. - Gil Favor
Somewhat related, my favorite Kahlil Gibran story:
''It is easy to forget that in the main we die only seven times more slowly than our dogs." Jim Harrison–The Road Home
Tanstaafl
My 6th grade math teacher had this on the chalkboard for the entire school year, and finally explained it on the last day of school.
“Write your injuries in dust, your benefits in marble.”–Ben Franklin
“Outside of a dog, a book is man’s best friend. Inside of a dog it’s too dark to read.”–Groucho Marx
One more:
“The future belongs to those who believe in the beauty of their dreams.”–Eleanor Roosevelt
“No act of kindness, however small, is wasted.”
Attributed to Aesop, but could precede him.
“For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and there you will long to return.”
Attributed, apparently incorrectly, to Leonardo da Vinci. Not really profound I guess but if you are a pilot, it sure nails it.
“For to everyone who has, more shall be given, and he will have an abundance; but from the one who does not have, even what he does have shall be taken away.” Matthew 25:29
“Either we are alone in the universe, or we are not. Either way, it’s a staggering thought.” - Carl Sagan (attrib.)