When the policeman asked O'Ryan where he was headed, O'Ryan said "California" and identified Johnson as "an Olympic gymnast. ... She's on TV now."
"I'm meeting her there and, uh, I'm going to try to get her to marry me," he said.
The Alabama policeman issued O'Ryan two tickets, one for not having insurance and the other for an expired license plate.
O'Ryan was a former Olympic hopeful before an injury caused extreme depression, a friend told ABC News.
He reportedly lived in the Florida RV park for less than a year and was considered a "loner" to neighbors.
"He didn't seem to associate with too many people," neighbor Dennis Cronin told ABC News' Jacksonville affiliate WJXX.
"He was just weird," another neighbor, Lorynn Thomas, said.
It's a different picture than a friend of O'Ryan's painted of the University of Florida graduate.
O'Ryan graduated with a degree in engineering and even tried out for the Olympic rowing team, but hurt his back and became extremely depressed, the friend said.
Larry Robinson, who co-operates the RV park, acknowledged O'Ryan's back injury and said the man had trouble walking but turned down all offers to help.
"He was real independent," Robinson told The Florida Times-Union. "I was going to take his mail to him ... but he said, 'No. I don't want no help.'"
O'Ryan has no criminal record in Florida.
ABC News' Alex Stone contributed to this story.