It's not uncommon.
"Yeah, you know, definitely it takes a little bit of time to get used to the speed," Stills said. "And, you know, everything picks up a lot faster."
That concept is something the talent from Encinitas, Calif. has been working on becoming accustomed to, as he said the speed of practice and games is even a change.
"In practice the ball might come out quick, but the speed in the game is just so much different because Landry's under pressure or, you know, different things like that," Stills said. "So I'm definitely getting more confident when it comes to playing in games, and that's all I can do is continue to get more experience out there."
The fact of the matter is maturing within a college offense involves some players' confidence, but others already have that confidence and just need repetition.
Stills' is the latter case.
"Right, you know, I don't struggle with confidence," Stills said. "But, you know, it's just I'm just out there doing what I'm told to be doing."
The biggest thing is just getting on the same page as quarterback Landry Jones.
"Yeah, most of the time it's been my fault," Stills said about being off on some of the routes. "And I feel kind of bad because Landry's kind of taken some of the blame for that, but, you know, I've got to pick my speed up and get on the same page as him."
But Stills said he's not far off.
"It's just little things when it comes to those routes," Stills said. "You know what I mean? You got to get out there and come out of the break faster and just continue to come down to the ball and just some things like that, so, you know, I definitely just like I said need to get more experience in the game."
So, while he's working on learning the speed and becoming more experienced in the offense, Stills said he's just doing what he can and staying within himself.
"If the ball's coming my way, I'm going to catch it," Stills said. "If it's not, then it's not, and, you know, I understand that, you know, obviously we had a huge win last week and the ball didn't come my way that many times. And I'm happy with that.
"You know what I mean? If the ball's going to come my way, I'm going to catch it, and if not, then that's fine. I don't really have any big expectations. Like I said before from the beginning, you know, I'm going to do what they tell me to do, and that's all I can handle."
And when he masters that, Stills is going to be a really solid player for the Sooners.