Humor is a funny thing.

Have you ever thought much about why we laugh at things?
 ...I mean, beyond the obvious reason that something is humorous.
That is, what is the underlying cause?
I hadn't ever given the matter the time of day until I read a quote by Mark Twain, "Everything human is pathetic. The secret source of humor itself is not joy but sorrow. There is no humor in heaven."

That perspective played in my mind for quite some time ...until I came to conclude that it was true. I think of my favorite jokes, amusing movies, laughable songs, hysterical books... Humor in sorrow? I think yes.
The most epic comic strip ever, Calvin & Hobbs, is classic example of this.

YouTube can be an excellent source of humor. For example ...a little Tim Hawkens:

 

Or a bit of Fry and Laurie:

Or  ...Julian Smith and his grandma:

 

Or Mark Gungor:

Or our dear Vice President:

Even King Solomon concluded likewise, "I said of laughter, It is mad: and of mirth, What doeth it?" (Ecclesiastes 2:2), and yet our dear, sweet Lord knew we'd need laughter and mirth to make it through this sore travail of life under the sun, "Then I commended mirth, because a man hath no better thing under the sun, than to eat, and to drink, and to be merry: for that shall abide with him of his labour the days of his life, which God giveth him under the sun."

Zig Ziggler tends to agree that humor is healthy (taken from his book Courtship After Marriage):

"A gentleman moved into a home for the retired and on the first day found himself seated directly across the table from a widow. After a few minutes he became uncomfortably aware of the fact that she was staring at him. He tried to avoid her gaze but to no avail; those stares kept coming. Finally, after several minutes of this, he asked her why she was staring so intently at him. She responded, "I'm absolutely amazed!"
MAN:         Amazed at what?
WIDOW:    The incredible resemblance you have to my third husband! Your color, your size, your height,                        your weight, your mannerisms, everything reminds me so completely of my third husband!
MAN:         Your third husband! How many times have you been married?
WIDOW:    Twice."

Mr. Zigglar's friend, Dr. Isaac The Clown, gives us some marvelous reasons for developing a sense of humor:

"Laughter is one of the greatest mental tonics known to man. It is the second most powerful human emotion we as people can express (the first being love). Laughter can dispel anxiety, help manage stress, depression, fear and worry. It can stimulate the healing process. Laughter provides strong medical, psychological, social and even spiritual benefits. Laughter is like internal jogging. It enhances the respiratory system, helps oxygenate the body, relax tense muscles, and is an all around pain killer. It will lower pulse and blood pressure. Laughter can pave the way for a new and exciting outlook on life. It is the universal communicator that can cross all boundaries of race or culture.
You can't laugh and be mad; you can't laugh and worry. Stress, worry and laughter are not compatible.
Laughter is low calorie, caffeine free, no salt, no preservations or additives, 100% natural, and one size fits all. Laughter is truly God's gift. You can get high on laughter but never OD.

Laughter is contagious. Once it starts, little can be done to stop it. Laughter never felt bad, committed a crime, started a war or broke up a relationship. Laughter is shared by the giver and the receiver. Laughter costs nothing, and it's nontaxable.

Laughter is a trend setter. If we can find ways to laugh first thing in the morning, it may, in fact, set the trend for the rest of the day. One of the most constructive uses of laughter is when we can laugh at ourselves. If we can laugh at ourselves, we leave little room for others to laugh at us.
Humor can be found in just about every daily situation. We just need to stop and think, and just take a good look around us and we can always find reasons to share joy.
Laughter is saying, "I'm O.K. You're O.K." It's a way we can accept what we can't change.
The clown inside of us need not be the one with a bright colored costume and painted face. It may just be a reflection of something that was lost sometime ago. The personal clown inside of you may be the one who felt that life was a joy and well worth living. He or she may be the one inside of you that needs other people, and that can live in harmony with others. Laughter can be the driving force to make life alive again."

Ah, yes! Well said, good doctor! Mirth is medicine for the soul!!! (see also Proverbs 15:13 & 15 and Proverbs 17:22)

Mark Twain said, " Every man is a suffering-machine and a happiness-machine combined. The two functions work together harmoniously, with a fine and delicate precision an the give-and-take principle. For every happiness turned out in the one department the other stands ready to modify it with a sorrow or a pain - maybe a dozen."

So in essence, laugh a lot. 

But, Mark Twain also said, "Grief can take care of itself; but to get the full value of joy you must have somebody to divide it with."

So, better yet, grab yourself someone... and laugh a lot with them.