This song was written for the soundtrack of the movie "The Bucket List" and is trying to capture the spirit of that film. After writing the lyrics for the song, John Mayer said, "I don't know how much harder it gets than to see a beautiful, bittersweet movie and then have to write a song that matches the tone". You can also watch the official video version here: Say.

Take all of your wasted honour
Every little past frustration
Take all of your so called problems
Better put 'em in quotations

Say what you need to say (x7)
Say what you need to saaaay...

Walking like a one man army
Fighting with the shadows in your head
Living out the same old moment
Knowing you'd be better off instead
If you could only
Say what you need to say (x7)
Say what you need to saaay...

Have no fear for giving in
Have no fear for giving over
You better know that in the end
It's better to say too much
Than never to say what you need to say again

Even if your hands are shaking
And your faith is broken
Even as the eyes are closing
Do it with a heart wide open... wide...

Say what you need to say (x7)
Say what you need to
Say what you need to
Say what you need to say...

TAKE ALL OF YOUR...= The first paragraph is actually just one sentence, so we should read: "take all of your wasted honour, your past frustration and your problems and put them in quotations".

SO CALLED= Incorrectly or falsely called (usually spelled with a hyphen: so-called). "Your so called problems" are problems that are not real. They look like problems to you, but if you put them in perspective you’ll realise they’re not real problems, it’s all in your head.

BETTER PUT ‘EM= You’d better put them. The expression YOU HAD BETTER + "infinitive without TO" means: SHOULD (we use it to give advise):
- If you feel so bad, you’d better go to the doctor = you should go to the doctor.
In colloquial English we often say "you better" or simply "better" instead of "you’d better":
- Listen, if you love her, better tell her right now.

PUT ‘EM IN QUOTATIONS= "Quotations" are punctuation marks used at the beginning and end of a word or sentence: "  "
We use quotations in two cases:
1- To quote the literal words somebody said or wrote:
- Shakespeare said: "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy."
2- To express that something is not exactly that:
- Oh yes, I know you’re always "happy", but is it real or just a façade? (By putting the word HAPPY in quotations, I mean that I don’t think you are really happy, or at least I’m not sure)
This second meaning is the one used in the song. If you put your problems in quotation marks, it means that you think they’re not real.

A ONE MAN ARMY= The phrase "one man" is here acting as an adjective, so "a one man army" is "an army made up of just one man". When more than one word acts as an adjective we often write it with hyphens: "a one-man army". Any phrase can be an adjective if we put it before a noun, even long phrases, for instance:
- Oh, I don’t like the I’m-always-right-and-you’re-not people

THE SHADOWS IN YOUR HEAD= Bad thoughts or fears that make you feel sad or worried.

LIVING OUT THE SAME OLD MOMENT= Remembering the same old memory over and over again. You remember it so intensely that it is almost like living that moment again, so you "live it out".

YOU’D BE BETTER OFF= You would be in a better situation, your situation would improve.

This paragraph has two different parts. The first part describes what your new attitude should be, what you are already trying to do: you should walk like a one-man army (all your being should have the same objective, with no doubts or conflicts) and you should fight your fears (the shadows in your head). The last lines reflect your present situation: you dwell in the past, always remembering that painful moment that makes you feel so sad, but deep inside you know that your situation would be much better if you stopped looking at the past and started moving to a new future "like a one-man army" and you could at last say what you need to say.

IF YOU COULD ONLY SAY...= The phrase IF ONLY is used to express a deep wish, a longing. For example, if you like travelling but have no money you could say: "if only I could go to India!" or "if I could only go to India!".

GIVE IN= Surrender, stop opposing.

FOR GIVING IN= Here, FOR means "Because", and after prepositions and conjunctions we use the verb in the -ING form.

GIVE OVER= The same as "give in" but stronger: to abandon yourself completely.

EVEN IF= Although.

EVEN AS= At the moment when.
- She’s coming here even as we’re talking = She’s coming here right now, at this very moment.
- You will start feeling better even as you drink this = The moment you drink this you’ll start to feel better.

EVEN AS THE EYES ARE CLOSING= It probably refers to the moment of death.

A HEART WIDE OPEN= If you do something with a heart wide open (completely open) you won’t be afraid of the emotions you’ll feel when you do it, you are ready to whatever you’ll feel when you do it. HEART is pronounced /hɑ:*t/.

Since this song was written to match the film "The Bucket List", I don't want to comment too much about it (I haven't seen that film). Having said that, I daresay the message of this song is: express yourself before it's too late. If you love someone, tell them; if you're breaking up with someone, tell them. Don't be afraid to say what's on your mind or in your heart. Life should never be lived as "what if?"