Johnson, who was recruited from Geelong Football League club Bell Park, spent time on the ground in the pool matches against both North Melbourne and the Western Bulldogs.
The 195cm rookie-listed forward was most impressive against the Kangaroos, booting a goal that brought the Cats fans to their feet.
"It was good to kick one," Johnson told afl.com.au after his team had won its way through to the qualifying finals of the pre-season competition.
"It was a cheap one but I'll take it. It's still a goal."
Johnson played 15 games in the VFL last season and booted an impressive 30 goals, but he says that level of football was nothing like the intensity he experienced on Sunday.
"It was flat-out, probably two times quicker than the VFL," the 24-year-old said.
"We train at a high intensity and playing in the VFL is good, but it was pretty crazy in the first 10 minutes I was out there."
Geelong's victories over the Roos and the Bulldogs mean Chris Scott's men will now play St Kilda at Etihad Stadium on Saturday night, and confidence among the players is high.
"I think it was really good to start the season with a couple of wins," Johnson said.
"We enjoyed the new format and it was good to get out there after the tough pre-season we've had.
"Even through the NAB Cup isn't that highly regarded, I think we did the work over pre-season so I think we deserved a couple of wins. Anything short of that would've been disappointing to me."
Barring a significant injury to one of his teammates, Johnson will begin the home and away season in the VFL. But he hopes promotion to the senior squad won't be too far away.
"If there's a spot and I'm playing well then hopefully I'll get a game," he said.
"That's what I'm here for and that's what I'm really striving for.
"It would be good to see the team go well and it would be good if I was in it."
Ben Johnson is a $92,500 forward in the Toyota AFL Dream Team competition
