The simple fact is he is an NFL student, a guy who wants to learn the intricacies of formations, reading blocks and trusting his broken field running instincts on punt returns.
But probably the most difficult adjustment he has to make is remembering things that are second nature for kids in junior American football, such as lowering his pads when expecting contact.
But Hayne's experience and class as a NRL star has NFL legends like Brian Mitchell, former running back and punt returner who's second all-time in the NFL in all-purpose yardage, behind 49ers legend Jerry Rice, telling Eric Branch from the San Francisco Chronicle: "He switches the ball from one hand to the other and uses the other to stiff-arm ... that's a lost art."
Lists of rugby and league players who have the physical tools to do the same as Hayne in the NFL have been bandied about this week, but the former Dally M winner will always trump those illustrious names because he's prepared to be a student of the game. Prepared to be a genuine rookie because he loves the game.
His preparation for games is Brad Thorn-like. He used to sleep with the hotel mattress on the floor in Origin camp, according to former Blues teammate Michael Ennis, because it treated his body better. He rolls around the Bay area in a used Mazda and according to local media he carries notes from his playbook stuffed into his shorts on the practice field.
According to Nick Walshaw from Sydney's Daily Telegraph, 49ers owner John York visited his team's training this week, which owners rarely do, and went directly to the running backs to check out this Aussie phenomenon.
The Sacramento Bee's Matt Barrow has watched Hayne execute footwork drills that rookies and second year players struggle with.
Legendary NFL coach John Madden says Hayne has all but sealed his spot on the San Francisco 49ers' final 53-man roster.
And if he doesn't, he will go to another NFL team.
Madden has a video game named after him that has grossed hundreds of millions of dollars.
Nike is preparing to make the 49ers number 38 Hayne jersey in anticipation of demand. Now you don't want to disappoint Nike, do you?
The pathway for athletes of Hayne's calibre has been forged, but the commitment shown is what's setting the former Parramatta Eels fullback apart from those who will now be flirting with the romantic notion.
He spent weeks with a renowned sprint trainer in Sydney in the off-season before his decision and went to visit the Seattle Seahawks and University of Washington to improve his skills.
A lot of rugby and league guys watch the NFL, have a team they follow and play Madden on PlayStation, but few would seriously throw away the comforts and riches of a professional sports career to do this.
League in Sydney, even more so than rugby in New Zealand, is a fishbowl.
Hayne had floated to the top and was sick of banging his head into the same piece of glass.
But he has the inner drive and, most importantly, the genuine love of the game to accomplish what no one on the wrong side of 25 from league or rugby has done before.
All aboard.
