(CBS News) INDIANAPOLIS -- I'm always skeptical of junior high teachers who smile, especially the ones who smile as broadly as Dan Stroup.
It seems like he really does care about them -- even if caring for junior high kids might seem impossible.
"Well I do," Dan says. "If you spend time with them, you love them."
Dan teaches an eighth-grade Bible class at Heritage Christian School in Indianapolis. But what he's most known for are his own writings: hand-written letters to his students on their birthdays.
Every kid in every one of his classes gets one. That's 105 personalized letters -- and that's just the beginning.
Melissa Bird was in Dan's class in 1985.
"Absolutely, every year, like clockwork, you know you're going to get a letter from Mr. Stroup," she says.
Ryan Bucher had him in 1989.
"I've missed birthday letters from my family, but I've never missed a letter from Mr. Stroup," Bucher says.
And Amy Lex hasn't missed one either -- not in 27 years.
"Growing up, going away to college, moving, I've lived in several states, and to think I still get these letters from Mr. Stroup," she says.
A long time ago, Dan made a decision: to send birthday letters to his students indefinitely. At the time, he had no way of knowing how the school would expand like it has -- or even that he would still be teaching 30 years later. But here we are: 2,800 birthdays and counting.
"I haven't had an end game on this," Dan says. Asked if he plans to retire soon, for the sake of his wrist, he replies, "I don't know, I haven't found a good time to stop."
What used to take him a few minutes a week now takes up to three hours a night -- an average of nine letters per day. Although really, his biggest problem is that he refuses to computerize the operation and insists on actually keeping up with all these people.
"He actually remembers who I'm married to, he remembers how many kids I have," one former student says.
"That's what's crazy," says Bucher. "I don't know if he's talking to my parents. I don't know if he's talking to my siblings."
"I don't know how he does it," says Bird.
He does it by attending reunions, weddings and baptisms -- pretty much any event he's invited to.
"I just want them to know that I knew them and that I cared," Dan says.
And lest anyone ever forget that, there's always a reminder in the mail.To contact On the Road, or to send us a story idea, e-mail us.