One role in particular was repeated more than any other, though, when those who knew Dickinson talked about him Tuesday: encourager.
"He was just an optimistic person, always with a smile on his face," said Phil Cohen, whose relationship with Dickinson goes back 20 years.
For Cohen, the owner of the Chain Reaction bicycle shop in Martinez, Dickinson was an encourager on the long training rides they would take out of Augusta. If Cohen ever fell back, Dickinson always slowed and pumped him up with his words.
"He wouldn't leave me behind," Cohen said.
Dickinson was a longtime cyclist and even crossed the country in 1993's Race Across America. He was pedaling to work at Dwight D. Eisenhower Army Medical Center around 6:30 a.m. Monday when he was hit from behind by a car. He died a few hours later from his injuries; he was 57.
Charlie Bussey, 76, was driving the 2003 Buick Regal that ran into Dickinson. Charges have not been filed, pending the outcome of an investigation into the circumstances surrounding the crash.
Cohen said Dickinson never shied from away from a challenge, whether it was cycling cross country or, more recently, climbing Mount Whitney, the highest summit in the contiguous United States.
"His days were definitely well-spent," Cohen said.
Cycling was a passion, but it didn't define him. The role he treasured most was husband and father to his four children, said friend Brian James.
"If anybody was a family man, it was Dan," James said. "He was always talking about his family."
James cycled with Dickinson roughly six years and called him a "great cyclist" who was always concerned about anyone who rode with him. That trait carried over to his work as a general practitioner in the family medicine clinic at Fort Gordon's hospital.
Dr. Mary Lewis, a pediatrician who worked with Dickinson, said he made an effort to know everyone on a personal level. He would be the listening ear and the concerned friend whenever someone was going through a rough time, Lewis said.
That sensitivity figured prominently in his practice as a doctor and made him a natural with children. Lewis said her office was filled with crying parents Tuesday who praised the care and concern Dickinson had shown toward their children.
"For him, medicine was a natural thing; it came effortlessly," Lewis said.
The staff at Eisenhower is like a family, and Dickinson was a true encouragement in the tight-knit group, Lewis said.
"We're going to miss him," she said. "It's not going to be same without him."
Doyce Johnson was planning a trip to Yosemite in three weeks with his longtime friend. They had made their final preparations over breakfast Saturday, then followed it with some mountain biking. In all their adventures, Dickinson was the one they counted on to make the best of a situation.
"It didn't matter how bad things got," Johnson said. "He was always happy."