(CNN) On Thursday, as Larry Johnson waited for his college commencement to begin, he snapped a selfie and posted a self-congratulatory tweet to Twitter.

"My goal was to graduate before I reached 100 years of age," he wrote. "I made it with 33 years to spare."

The 66-year-old's tweet exploded as the Twittersphere congratulated him on receiving his undergraduate degree in journalism from Georgia State University in Atlanta. Johnson -- now dubbed a "legend" and an "inspiration" -- said he tried to read them all.

"I got overwhelmed with it after awhile," he told CNN on Saturday.

My goal was to graduate before I reached 100 years of age. I made it with 33 years to spare. #gsu18 pic.twitter.com/eUQtGTTKaw

Among all the congratulatory messages were a few thanking Johnson for sharing his accomplishment. Their own educations had been delayed or derailed, and they felt it was too late to get their degree or that they'd missed the window.

"You're truly and inspiration," one user wrote. "I want to go back to school but felt it was too late .... and I'm 28. I think you gave me the push I needed."

"This makes me feel better as (a) 23 year old rising 'senior' with 3 semesters left," another said.

"This is so inspiring," another chimed in. "I always feel like I have missed the train. I won't stop, I will keep pushing."

"From my point of view," Johnson said with a chuckle, "a 28-year-old saying that they've missed their chance at higher education seems a bit odd."

A roundabout college career

Johnson described his college career over the years as "very insane and funny."

He first enrolled at GSU in 1969, but he wasn't really interested -- he spent more time hanging out in a common area and playing guitar, he said, which dealt a toll on his GPA -- a deficit he never fully recovered from. He went back in the mid-1970s, Johnson said, "but I couldn't think of a compelling reason to continue."

When he enrolled in classes in the 1980s, he was much more serious. But his wife, who had Type 1 diabetes, was in the final days of her life then, Johnson said.

"I spent a lot of time taking care of her, and the balance of going to school and work and caregiving -- it made school be the lesser of the priorities."

Johnson's wife passed away due to kidney failure not long after he started classes.

Several years ago, after retiring from a career in IT, Johnson was in downtown Atlanta meeting a friend and expressed interest in returning to school. It was days before the start of the semester, but his friend encouraged him to see if he could register.

So Johnson went and filled out some forms -- the school still had his records, he said. He received an email the next day, telling him he could start classes on Monday.

'We've all got a finite number of years'

Johnson had always been interested in writing and had been operating blogs since the late 1990s, he said. He'd also done some freelance reporting and has a news site, the Cobb County Courier , where he covers local news and county government, so he knew he wanted to go back to get his journalism degree.

Thanks to a Georgia program , students over the age of 62 can have the cost of their tuition waived, and Johnson took advantage of it.

"By the time I entered the journalism department at GSU, I was already pretty certain that I wanted my final career in life to be journalism," he said.

Johnson recognized folks can be discouraged if feel they've missed the opportunity of a college degree, and that there are limitations as people get older. "But it is possible to do something approaching what it is you want to do," he said, whatever that might be.

I entered Georgia State University in the Fall of 1969. This evening, after roughly 49 years I'm finally having my commencement ceremony. If I'd been just a bit more patient I could have made it an even 50 years. — Larry Felton Johnson (@larryfeltonj) May 10, 2018

"It's a little nonsensical to me for anyone to say, 'It's too late to do what I want to do,'" he said. "We've all got a finite number of years, and a person should ask themselves, 'What else am I going to do?'"

"Say I've got five years left to go," he said. "I want to spend it doing journalism."

"What else are you going to do in the intervening time?"