My SAT math scores weren't the greatest, okay, but I did get into American University. 

And a few years after I graduated, there was a big rivalry in the track and field world between Dan O'Brien and Dave Johnson. Reebok had this whole campaign around "who's the greatest decathlete: Dan or Dave?" Simultaneously, the New York Giants were having a quarterback controversy between Phil Simms and Jeff Hostetler.

So, I had this brilliant marketing idea: I'd make a thousand t-shirts that said "Who's New York's best quarterback? Phil or Jeff," and I'd bring them to the customers—70,000 Giants fans tailgating before the game.

Selling a thousand shirts would be a breeze...

I borrowed money to get the shirts made, splitting the cost with my roommate, Spit. It was all my savings. We drove Spit’s mom’s car to the stadium on game day, ready to make a fortune. 

"Do they shrink?" one guy asked, inspecting the shirt like it was a fine silk. 

"What sizes do you have?" another inquired, as if we were a mobile department store.  

And then there was the bargaining. "Can I get it for $7? $6? $5?" Everyone wanted a deal.

It took us a full 15 minutes to make our first sale, and we quickly realized we were in over our heads. 

Three minutes later, security guards kicked us out and banned us from Giants Stadium for a year. We had bootleg shirts with the Giants logo, and we didn't have a license to sell anything in the parking lot. 

It was only later that I did the math, when it was way too late. To sell all the shirts, we would've had to move 7 t-shirts per minute for three hours straight. Physically impossible. The most I could realistically sell was maybe 40 shirts total. I hadn't considered the time it takes to negotiate prices, answer questions about sizes, or even just carry the shirts back and forth from the car. 

If I had just taken five minutes to think it through, I could've saved myself so much hassle. But hey, that's the beauty of being young and hungry. You take risks, you make mistakes, and end up with pretty entertaining stories down the road. 

The lesson: Take the time to do the math and be realistic about your resources. Measure twice, cut once.

It might just save you from a bootleg t-shirt fiasco.