Cooper, who has been playing in Japan in recent years, was called up as cover after a four-year hiatus by coach Dave Rennie when first-choice first five-eighths James O'Connor was injured.
But he was enjoying working out with the side in Perth ahead of Sunday's Test with the All Blacks.
Cooper said his dropping from the Reds in 2018 and his return to club rugby had been transformational for him.
He had realised he enjoyed passing on his knowledge, something he hadn't had the patience for earlier.
"At Super Rugby and Test level, I would get frustrated when someone didn't understand their role, or missed a jump on a play, forget a little bit of knowledge because, to me, you should automatically know that at that level.
"I think that was an error in judgment on my behalf, instead of putting in the time and effort to help other people because everyone learns in different ways," he told rugby.com.au.
At Souths, where there wasn't the resource in coaching or players that there is at the higher levels, he said he found patience.
"That was probably the first time I enjoyed and got more satisfaction out of seeing other players learn.
"You'd be out on the field and there would be something you have a conversation about, or you could see guys working at week in, week out, and you see the lightbulb moment that they realised and understood what was going on. That was a moment for me that I go so much satisfaction out of," he said.
At the same time, he said his call into the squad was another chance for him to learn more.
"The things I've been able to learn, and whether I go back to Japan after the Rugby Championship I'm not 100 per cent sure, but I'll have a wealth of footballing knowledge in terms of what I've been able to learn, and gain about myself, being back in this environment.
"It hasn't been a focus of mine to come in just to play games. If I can grow as a man, grow as a rugby player, and take that back to Japan and pass that on to other people, that's a great reward," he said.
New Zealand-born Cooper praised the effort coach Rennie had put into uniting the squad and reflecting the cultural make-up of the country.
"The first thing that I noticed was there was a real focus on inclusion, representing everyone in this team.
"In the squad, we have guys, Australian, Samoan, Tongan, Fijian-born guys, who have come from different backgrounds, so there's a real emphasis on everybody having their identity represented.
"I think when you look at Australia as a country, it's such a multi-cultural landscape, and to be able to see everyone represented is a great thing, and something I've really enjoyed," he said.