Any regular viewer of this show would know one of best pieces of advice I ever got was from my Italian dad, who upon looking at my grades as a kid once remarked, "Neil, stay humble. In your case it'll come in handy."

He was trying to remind me never to forget my limitations and never take success for granted should I do something with my life despite them.

Sure enough, I did, to which this Italian of few words would later say, "Only in America can my Neil be giving people financial advice."

We both chuckled at that.

But I got loud and clear what he was saying with that: He was telling me not to get a big head. Not literally, of course. Too late for that.

But figuratively. Don't start assuming success is a birthright or good fortune a guarantee. Never rest. Never coast. Never once think you're all that.

Because nothing destroys a good life, he'd say, like assuming you're good for life.

You're not. I'm not. We're not. Yet it's human nature to get ahead of ourselves, to live in the moment, and forget it's only a moment.

Democrats who win a big election and think they can't lose, now looking at awful poll numbers and fearing the next midterm election they can't win. Republicans now pinching themselves relishing this good fortune, forgetting it was little more than a few good months ago they were wallowing in bad fortune.

My boss once said it is harder to hold onto success than it is to achieve it. Yet most can't hold onto success precisely because they think it's a given once they have achieved it.

Life doesn't work that way.

I know, nothing profound here. But I think we screw up this one principle in life time and again. We assume character is built by how we handle the bad times. Who knew its greatest test is how we respond to the good times?

Because as my not-to-be-left-out Irish mom would say, "Life is a snapshot. Pray you don't look worse in the next one."

I think my dad just nodded. He never argued with history... or my mom.

Wise, indeed.

Watch Neil Cavuto weekdays at 4 p.m. ET on "Your World with Cavuto" and send your comments to cavuto@foxnews.com