AT THE age of 23, Collingwood's Nathan Brown is too young to have knees that resemble road maps.

But, two knee injuries and surgeries on both have left the joints punctuated by thick scars that remind him of his luckless 2011.

There are marks on his left knee from the anterior cruciate ligament repair he had in the pre-season, and a scar on the right from where the surgeon took the middle third of his patella tendon to mend the torn ligament.

Then, there's the angry-looking remnants of a long incision that runs from the top of his right knee to the bottom, crossing the scar from the tendon operation.

That was to fix the cracked patella he sustained on a hike in Arizona in June last year. 

"There were a lot of dark times," Brown recalled to AFL.com.au this week.

"You have some weeks in rehab where you don't want to be there. You try and do something and it hurts and you feel terrible, and feel so far away from being able to play again, let alone at an elite level.

"But, there were a lot of great times too, and a lot of learning.

"Yes, I missed playing footy and playing in another Grand Final but what I've learnt in the last 18 months is something so valuable that I'll hold dearly for the rest of my career and the rest of my life."

Brown underwent another operation shortly before Christmas last year to remove the pins and "figure-eight shaped" wire that held his patella together.

"Initially, we were going to leave that in all season but it wasn't allowing my muscles and quad to grow," he said.

"The scar was reopened and it was taken out, and immediately it felt so much better.

"There was about four months where I couldn't feel comfortable even driving a car. I couldn't keep my leg bent - I had to straighten it out every 20 seconds.

"It's so good to drive a car normally again."

When things got really tough, Brown would book a flight to Perth and seek solace in the company of twin brother and West Coast defender Mitch.

Mitch knew what Nathan was going through, having had his own knee reconstruction in 2008.

"He was massively important," Brown said.

"When I did it, we were still playing really good footy as a team and there was a chance of another premiership, and I wanted another one so bad.

"I was straight onto Mitch, talking about how could I get back quicker so I could be a part of it, if it happened."

The dream of playing again in 2011 wasn't to be after the mid-season accident, and Brown only returned to the senior field last month on Anzac Day against Essendon.

He was ready to play in the NAB Cup, but was held back by the medical staff as he continued to strengthen his legs.

It was a frustrating move after so long out of the game, but one he understood - and can accept even more now he's slotted seamlessly back into the game.

"I don't think I would have had as much impact as I've had now if I'd played in the pre-season," he said.

"I'd always go back to the thought I'd been out for 18 months and another couple of weeks wouldn't hurt."

Brown signed a two-year contract extension late last year, which gave him immense confidence given he knew there were no guarantees with his knees.

"I met with Bucks throughout the year and towards the end of it, and we had some really good chats about where we wanted to go and my future, and where I fitted in his team," he said.

As a result, Brown has entered this season with renewed belief in himself, his body and the club - and believes the past year has left him with a refreshed love of the game.

He enjoys the simple things, like being in a normal routine and not having to miss training sessions.

His knees are pain-free, and the only side effects he carries are a slightly enlarged kneecap on the right side and a minor loss of skin sensation under both.

He also doesn't take things for granted anymore.

"During the year, a mentor of mine, Max Hudghton, maintained the only regret he had in his career was that he didn't sometimes enjoy playing footy," he said.

"That really stuck with me. Out on the ground, I'm not nervous anymore. I just love being out there and I'm just so thankful for having the opportunity to be out there playing.

"It's made me enjoy the game a lot more and that's snowballing with me playing good footy."

The views in this article are those of the author and not necessarily those of the AFL or its clubs.

Jennifer Witham is a reporter for AFL Media. Follow her on Twitter @AFL_JenWitham.