By SEAN DIETRICH

One day you will laugh. I promise. Probably not today. Probably not tomorrow, either. But soon.

Right now you are a premature newborn, lying in the NICU, inside a plastic bubble, just trying to breathe. Your name is Harley. Your tiny heart is struggling to beat, and your little nervous system is doing its level best to keep you alive.

You have mini-electrodes, sensors, itty-bitty tubes connected to your frail preemie body, and a knit cap to keep your head warm. Your life is devoid of humor right now.

But someday, Harley, you will be a normal, healthy baby. And you’ll eventually do what all normal babies do. You’ll eat, sleep, cry, pee and seriously attempt to swallow your entire foot. And you will laugh.

You will also create digestive messes that will cause your parents to gag. Like the legendary mess my sister made when she was 9 months old and her cloth diaper spilled its contents into her crib. Whereupon my sister engaged in some good old-fashioned finger-painting on the bedroom wall.

After exhaustively cleaning the walls with Clorox, my father announced that he would not be eating meals again until his 90th birthday.

You will do things like that, Harley. You will grow. You will become handsome. You will stun us all with your talent. You will finger-paint.

But at some point in life, the sting of adulthood will find you. It finds us all. Someone will break your heart, you will become disillusioned or you will lose something precious. Your health will fail. You will experience sadness, loss or God forbid, spite.

You will learn that life is not as gleeful as depicted in the movies. Not every story has an idyllic sunset. There are no such things as unflawed heroes. Nothing works out the way you think it should.

The hard truth is, people can be mean, and life’s circumstances can be exponentially meaner. If you’re not careful all this will make you extremely constipated.

But humor will save you. Because humor is God’s gift to humans.

I once read a story about a young Jewish man in the Buchenwald concentration camp during the throes of the Holocaust. The young prisoner took it upon himself to constantly crack jokes, pull pranks and make his fellow prisoners laugh.

The comedian always had a large audience because the prisoners craved laughter. Sometimes this laughter would spread like a virus throughout the entire camp until prisoners were flogged into silence.

But even the beatings could not stop the laughter. Men laughed deep into the night. They laughed throughout the days of grisly labor. They laughed over their paltry bowls of gruel.

Buchenwald was a vision of hell itself, and yet the gaunt men in the striped pajamas could frequently be seen laughing until they wept.

The comedian later remarked that laughter was how they kept their dignity throughout the most undignified circumstances. It was how they kept themselves alive.

In my own experience, I have noticed that people with the best senses of humor are usually the ones who have seen life’s worst stuff.

Take Randy. My friend Randy is hysterical. Whenever Randy tells a story to a room, everyone slaps their knees so hard that they develop stone bruises. People laugh so hard they ruin their trousers.

The ladies in the kitchen always pop their heads out the door whenever Randy is mid-story, and they shout, “Tell us what Randy said!”

I always assumed Randy must have had the greatest childhood. I imagined that he must have learned his skill from a funny father, or maybe a humorous mother. But no. Randy grew up as an orphan.

Randy bounced around from foster home to foster home. He endured sexual abuse, neglect, abandonment and the unique brand of beuracratic ignorance that is the American foster system. And somehow, he learned to laugh in its face.

“I like to laugh until I cry,” Randy once told me. “Or vice versa.”

The thing is, Harley, nobody laughs at wonderfully happy things. You will find that the funniest moments in life are often the result of pain, suffering and misery. “America’s Funniest Videos” is only one example.

But laughter can neutralize the acid in your worst circumstances, and it connects you to something bigger than yourself. Something higher. Something healing.

Someday soon, when your tiny body is healthy enough to produce laughter, you’ll see exactly what I mean. Maybe it will happen when someone tickles you. Or perhaps a parent will place their mouth on your bare, newborn tummy and blow a loud raspberry.

At which point a joyous sensation will originate in your heart, rise upward through your chest, and exit your mouth. This peal of laughter will be the most glorious noise your mom and dad have ever heard.

Which is why I pray you never stop making that sound. And I sincerely pray the same for us all.