Cavuto: Life is short, but we don't have to be

He wants for nothing, but complains about everything.

About children who never call him, even though they do -- a lot.

Neighbors he insists are out to get him, even though they are not.

Angry and alone, he just sits and stews and this night I stop by he is loaded for bear.

He's seething over some delivery guy who left his mailbox open and refused to close it.

"Can you believe that," he tells me, "Second time this month!"

"I'm sure it was an accident," I tell him. But he's hearing none of it this night.

He proceeds to rattle off a series of similar slights. All silly. All stupid. All sad.

What happened to this guy?

This guy I used to know well when my mom and dad were alive

A contemporary of theirs, still bitterly marching on in life, years after they both left this life.

My mom used to dismiss his ways because she insisted he was a good soul. Then again, my mom would have said that about Usama bin Laden, because she had a good heart.

I thought a lot about my mom looking at this guy, hearing this guy as he criticized his kids, who'd do anything for him. Even his grandkids, who for some reason still think the world of him.

And then I thought about something my mom used to say about how you can tell a lot about a person by what gets them upset.

Little things? Little person.

Petty things? Petty person.

Yet no matter these annoying things, to my mom, at least, always the same person, always a good person. Yes, even this person. A person deserving of her kindness and an obligation I show the same kindness.

No matter what I thought, she used to say, "Neil, don't be thoughtless."

Then I remembered my mom when she was diagnosed with brain cancer and the dignity with which she handled that cancer.

I remember how she never complained, never said a bad word. Never judged the friend who should have called more often, just grateful he called at all and left it at that.

I think you can also tell a lot about a person by how they handle the really bad stuff in life. There are those, like this fellow I shake my head at this night who would sooner go to their grave with a chip on their shoulder. And those like my mom, who'd prefer to leave it without so much as a bad word out of their mouth.

I know. I'm biased. But I tell this fellow he'd do well to remember my mom, his old friend and how she smiled through far greater pain.

He tells me, "Save it for one of your 'Common Sense' things and preach about it on TV."

I told him I would do just that, hoping he gets the message.

I do so tonight, hoping the rest of us never forget that message. It's a simple message from a simple woman -- my mom -- who was right: Life is short, but that doesn't mean we have to be.

That's why I have such a problem with negative people. It's in my blood.