Let’s start with general definitions.
Mathematics is made of 50 percent formulas, 50 percent proofs, and 50 percent imagination.
“A mathematician is a device for turning coffee into theorems” (P. Erdos)
Addendum: American coffee is good for lemmas.
An engineer thinks that his equations are an approximation to reality. A physicist thinks reality is an approximation to his equations. A mathematician doesn’t care.
Old mathematicians never die; they just lose some of their functions.
Mathematicians are like Frenchmen: whatever you say to them, they translate it into their own language, and forthwith it means something entirely different. — Goethe
Mathematics is the art of giving the same name to different things. — J. H. Poincare
What is a rigorous definition of rigor?
There is no logical foundation of mathematics, and Gödel has proved it!
I do not think — therefore I am not.
Here is the illustration of this principle:
One evening Rene Descartes went to relax at a local tavern. The tender approached and said, “Ah, good evening Monsieur Descartes! Shall I serve you the usual drink?”. Descartes replied, “I think not.”, and promptly vanished.
A topologist is a person who doesn’t know the difference between a coffee cup and a doughnut.
A mathematician is a blind man in a dark room looking for a black cat which isn’t there. (Charles R Darwin)
A statistician is someone who is good with numbers but lacks the personality to be an accountant.
Classification of mathematical problems as linear and nonlinear is like classification of the Universe as bananas and non-bananas.
A law of conservation of difficulties: there is no easy way to prove a deep result.
A tragedy of mathematics is a beautiful conjecture ruined by an ugly fact.
Algebraic symbols are used when you do not know what you are talking about.
Philosophy is a game with objectives and no rules.
Mathematics is a game with rules and no objectives.
Math is like love; a simple idea, but it can get complicated.
The actual quote from the Webster dictionary:
trillion n
syn SCAD, gob(s), heap, jillion, load(s), million, oodles, quantities, thousand, wad(s)
Mathematics is like checkers in being suitable for the young, not too difficult, amusing, and without peril to the state. (Plato)
The difference between an introvert and extrovert mathematicians is: An introvert mathematician looks at his shoes while talking to you. An extrovert mathematician looks at your shoes.
A bit of theology.
Math is the language God used to write the universe.
Asked if he believes in one God, a mathematician answered:
” Yes, up to isomorphism.”
God is real, unless proclaimed integer.
Medicine makes people ill, mathematics make them sad and theology makes them sinful. (Martin Luther)
Vernon Pope 
I read through the sentences and chuckled at some of them. But as someone who still remembers high school thirty years later, I’m just not convinced that math and humor belong in the same sentence. Math and torture, perhaps.
It would seem that your age is between that of my wife’s and my own. I graduated HS 35 years ago. As for math – I was offered a full scholarship to university in maths; I was that good at it (back in the day). I didn’t take it.
I have to say, I’m in awe of anyone who can do mathematics. I even devoted an entire post to this subject once. My eldest son is pretty good at it too. I’ve often watched him working on a problem and wondered what precisely is going on in his head and why my brain just doesn’t work like that.
I have a theory, if you’re willing to test it for me. My theory is that the reason you (or anyone else) is having trouble with math is that somewhere early in your education, someone either mis-defined some terms, or skipped over one (or more) without defining it (them) – leaving you with a mystery that screwed up everything you tried to learn after that.
Well, I’m not sure if you’re right or not, but my mother says that I was ill when the kids in elementary school started studying math for the first time. I was off for two weeks and when I returned I had no idea what was going on. According to her, my confidence in the subject never recovered.
I’m not sure that I quite buy her theory myself, but who knows? I never had trouble with any other subjects at school — even sciences — as long as they were about something other than pure mathematics.
Actually, her explanation and my theory work very well together. You were sick during the very weeks that the foundation was being laid, and nobody backed up and put it down for you. The terms defined during those weeks were essential to having any chance at understanding what was going on. All other subjects were built on vocabulary you picked up as you went along – history, reading, civics – but you can’t build a mathematics vocabulary if you don’t understand what numbers are and how they add or subtract. My guess is that this is PRECISELY what you need to fix.
We’ll, it sounds plausible. It’s certainly a lot more comforting for my self-image than my long-held alternative theory: incorrect assembly and a lack of the requisite parts. There may still be hope for me after all!