This story was originally published at the Urban Innovation Exchange.

There are some people who seem to always be happy. Without a care in the world, they stroll delightedly through life accompanied by contagious enthusiasm. Such people sometimes stir in others a mix of affinity and slight suspicion. "Nobody is this happy," we think to ourselves.

In truth, nobody is this happy -- except maybe Charlie Cavell.

The overwhelming sense of optimism that Cavell exudes is forgivable because of his successes -- both in his personal life and with his nonprofit, the Pay it Forward Initiative. He’s not just a talker, he’s a doer. He is also 21 years old.

The Pay it Forward Initiative (PIF), a nonprofit Cavell founded in 2010, provides employment opportunities, job training and skill services to jobless Detroiters ages 18 to 24.

Pay it Forward’s primary offering is a 16-week internship program. The program places interns in jobs with local partner organizations, such as Quicken Loans and The Salvation Army. During the course of the internship, PIF provides a standard program package of weekly counseling sessions, a transportation stipend, financial management and entrepreneurial classes, as well as wages totaling $2,400. The partner organizations where the interns are placed do not incur any costs.

As part of PIF’s comprehensive approach to job placement, interns are evaluated to determine the prerequisites for their career success. This orientation meeting allows PIF to recognize and administer additional services such as childcare, education and connections to other social service providers.

At the end of the internship, interns leave with a stronger resume having learned valuable job skills. PIF also arranges two letters of recommendation and a job offer or opportunity for continued education.

The curriculum administered by PIF was developed in conjunction with faculty at Wayne State University, where Cavell attended college.

A recent graduate of WSU's Social Work program, Cavell believes his purpose is to help and speaks about enabling a "level playing field" and equal access. He insists that a holistic perspective is key to providing long-term employability, which means equipping people not only to learn, but to also become what he calls "change agents."

For Cavell, there is little ambiguity about the direction this agency should be focused -- the individual. While he believes that ultimate responsibility for transformation and success lies with each person, he is uniquely aware that a little help is necessary.

At 16, after growing up in and out of foster care, Cavell was adopted by a lawyer and college professor. For him, being adopted out of the foster system into a nurturing home was like hitting the lottery -- "moving on up to the Eastside," as the song goes. After graduating high school, Cavell won a scholarship to run cross country at WSU.

At WSU, with the help of The Blackstone LaunchPad, a student entrepreneurial incubator, Cavell was able to start Pay it Forward. To date, his initiative has matriculated 30 interns and raised an impressive $100,000. Mind you, this is just in the first two years.

Cavell continues to pay it forward – with great purpose, passion and palpable joy. At 21, he is an inspiring example of enthusiasm acutely focused to create not just positive "energy," but real opportunity and impact.

This story was originally published at the Urban Innovation Exchange. For more profiles of Detroit innovators, visit UIXDetroit.com.

Video by DETROIT LIVES!

Also on HuffPost: