I was just sitting there minding my own business when disaster struck and my life forever changed.

It was early March, my first day as a new fifth-grade student at St. Xavier’s Catholic School in Junction City, Kansas. Because I was nervous, I decided the best thing to do that day was to mind my own business, which worked out pretty well.

Until Sister Susanne, the music teacher, walked into the room.

Sister Susanne marched to the front of the room and held up a deck of flash cards with musical notes on them. She pulled one card out of the deck and,  of course, pointed at me, the new guy.

“But I’m minding my own business,” I thought to myself.

Sister Susanne took out some sort of round thing and blew into it and  pointed to the flash card.

“Sing,” she said.

“Sing what?” I thought.

Sister Susanne blew into the round thing again and pointed to the flash card.

“SING!” she said.

So I did and every one of my new classmates laughed at me.

I have not sung in public since — well, at least not sober.

Last Tuesday night, my wife and I were sitting in our seats watching the newest production at The Second City in Chicago.

The Second City, of course, is the comedy improv club that has launched the careers of hundreds of comedy legends.

My wife and I loved The Second City, and if you haven’t been, I urge you to go the next time you’re in Chicago.

But be careful.

I thought I was being careful. We were sitting in the fourth row — close to the stage but not too close.

I was minding my own business, sipping a beer and laughing at appropriate times — but not too hard because I didn’t want to attract attention to myself. I just wanted to mind my own business.

It was near the end of the show when Tyler Davis, one of the six extremely talented and funny members of The Second City cast, jumped off the stage pretending to be armed and looking for a hostage.

Like everyone else in the audience, I laughed at Tyler. Then he grabbed my shoulder.

“YOU! GET UP!” Tyler screamed.

Hoping to lighten the mood, I picked up my wife’s class of wine and took a sip.

Tyler made a joke about me sipping wine, then he pulled me up, and the next thing I knew I was sitting backstage listening as Tyler explained what he needed me to do.

Tyler said that it was an important night for the cast. There were agents and casting directors in the audience, he said.

“So,” he said, “I’m going to go get a sheet of paper that I want you to read to the audience. Then …”

Well, I don’t know what else Tyler said. My mind sort of froze at, “I want you to read to the audience.”

A minute later, Tyler came back with the piece of paper and a microphone. Then he said, “Oh (Bad word), you’re on.”

Seconds later, I was standing on stage alone with a microphone and a piece of paper in my hand and 300 people staring at me.

Did I mention I was minding my own business?

I read the speech, and the audience laughed. Of course, the audience also laughed when I tried to do the Electric Slide with Kimberly Michelle Vaughn.

So I’m thinking the laughs were “Thank God I’m not that guy” pity laughs.

Later, I sat on stage with the scarily funny Nate Varrone for what was supposed to be a funny improv scene. Nate was funny. I sat on stage.

The rest of my time on stage is sort of a blur although I vaguely remember sticking a piece of black tape onto a semi-naked Jeffrey Murdoch’s left nipple. It wasn’t what it sounds like.

So, to sum up. I was minding my own business and the next thing I knew I was trying to ad lib with professionals, dance the Electric Slide and stick black, duct tape on the nipple of a semi-naked man.

But, you know what?

I didn’t have to sing.