As careers go, it's been a short one, only 15 years. But David Menasche has spent every minute of it teaching English at Coral Reef Senior High School in Miami, where his former students number nearly 3,000.

Now 40, he's battling stage-four brain cancer. After three surgeries, 2 1/2 years of chemotherapy and 30 rounds of radiation, he is losing his battle against cancer. So in his final months, Menasche is doing what most teachers only dream of: He's traveling the country, visiting his former students and asking: Did I make a difference?

"I am at the end of my life," he said recently. "I don't know how much longer I have left, and I just wanted that sense of satisfaction that the time I did have I used well."

After a seizure this summer led to brain swelling that took away all but a sliver of his vision, Menasche realized he'd never return to the classroom again. The seizure also limited use of most of the left side of his body, forcing him to go on disability. But rather than sit at home, he got an idea for a "vision quest" to reconnect with former students. In August, Menasche put out a call on Facebook, asking if any Coral Reef alumni had couches to offer.  More at USA Today