TORONTO — At 31, Leandro Barbosa was the oldest player on the roster when he joined the Golden State Warriors before the start of the 2014-15 season. His teammates were so young, they might as well have practiced at recess. Stephen Curry was just beginning to edge toward global stardom, and the Warriors had not won an N.B.A. championship since 1975. Nobody was using the word “dynasty.”

“We were underdogs,” Barbosa said. “No one believed that we could go so far.”

The Warriors had signed Barbosa, a guard known as the Brazilian Blur, in large part for his experience, and he found himself surrounded by willing learners. He recalled how Curry and Klay Thompson were always peppering him with questions.

“They would just nod their heads and say ‘Thank you,’” Barbosa said recently in a telephone interview. “It’s kind of funny to think how big they are now.”

Barbosa was there for the start of what has been an exhilarating five-year ride for the Warriors and their fans, and a soul-crushing stretch for pretty much everyone else. Curry and Thompson — the Splash Brothers — were plenty good even then. But few could have anticipated all the records their Warriors would smash, and all the rings they would chase.