They're seasoned entrepreneurs who understand competition, profitability, risk management, and proprietary sales channels. They know how to manage others to get things done. It's just that their businesses weren't legitimate. And that's why many of these men are in prison today.

I was invited recently to share my views about leadership and personal development as part of the Prison Entrepreneurship Program (PEP) at the Cleveland Correctional Center in Cleveland, Texas. It was my first introduction to this storehouse of untapped potential. I was impressed when I was welcomed enthusiastically, was asked smart questions, and received heartfelt, handwritten thank you notes from almost every single attendee afterward.

Houston-based PEP, founded in 2004 by former Wall Street investor Catherine Rohr, is connecting Texas felons with the nation's top executives, MBA students, and politicians, all of whom are helping them fulfill PEP's motto: "Changing the future by reconciling the past."

I hope I gave them some useful food for thought. They certainly did for me. Here are just three thoughts I've been pondering in the days since:

1. You can transform yourself regardless of the scenery.

These men are changing their lives in a scary and dangerous place, and any entrepreneur can learn from that. We all have dark places to walk through in our business lives. Their example is inspiring, not to mention a little shaming when I think about those times when I might have complained in the past about things like parking or the size of my office.

2. Attitude is everything.

If they can muster a positive attitude in prison, surely we can do so outside those walls. It begins with learning from the past and doing what you can to mend it. Through simple behaviors such as courtesy, genuine curiosity, and follow-up, you can build the passion you need to create a better future.

3. Everyone needs a support system.

Don't believe those who say "It's every man (or woman) for himself." Personal success depends on your commitment to a community. The PEP "gated community" (as many there refer to it) educates and mentors inmates during their stay, as they quipped. Then PEP helps them reintegrate into legitimate society "on the outside."

It's true; these folks' behavior caused their incarceration, but they are taking active steps to better themselves and leave that past behind them. Next time you feel sorry for yourself or make a mistake, remember it's never too late to learn from it and move on.