That's not exactly breaking news as presumably all quarterbacks need to be confident in order to thrive in the league.
"I knew that (Brady) was better than me in my first day in the NFL," the 26-year-old Garoppolo told Joon Lee of BleacherReport.com. "Naturally, you're the rookie and he's the veteran, but you have to have that mindset, that you want to be the starter.
"Even when I was a little kid, my brothers, whenever we would play, I would literally always think I was going to win. I wouldn't, but I would always think that. It's like when I go to New England, when I first got there, I thought in my head, 'I'm better than this dude.'"
When asked to clarify if he thought he was better than the five-time Super Bowl winner, Garoppolo said the following:
"It was always a quiet confidence. I would never speak that."
Garoppolo said he didn't share his feelings with Brady, but admitted there was a healthy competition between the two.
"We got along, but there were always times where we wanted to kill each other," Garoppolo said. "It was a healthy, competitive relationship."
Garoppolo was traded away by the Patriots midway into last season for a 2018 second-round draft pick. He quickly hit the ground running with the 49ers, posting a 5-0 mark as a starter before parlaying that success into a five-year $137.5 million contract in February.
In his six games for San Francisco, Garoppolo completed 67.4 percent of his passes for 1,560 yards, seven touchdowns and five interceptions.
Garoppolo also won his two games he started for the Patriots in 2016, when Brady was serving his four-game suspension for his part in Deflategate. Garoppolo injured his right shoulder in the second game that season, and was replaced by Jacoby Brissett for the final two contests before Brady's return.
Brady threw for a league-best 4,577 yards along with 32 touchdowns and only eight interceptions last season.