Steve Moses, the 22-year-old college student from Gouverner, New York, took home Big Brother's $500,000 grand prize on Wednesday night -- and he can't believe it.

"Lots of feelings," Moses told ET in the Big Brother backyard after his win. "All of the feelings. Of the things that were possible, when I applied for the show, this wasn't one of them."

"I knew when I applied, I would never hear anything," Moses continued. "When I heard something, there was no way I would actually walk in the house. Walk in the house, I'll be out the first week... and, every step I thought was my last step. This was never a possibility. This was never a possibility." 

WATCH: Julie Chen Talks the Biggest Big Brother Shock Ever, All Stars 2 and Embracing "The Chenbot"

Moses made a huge game move on finale night: He evicted front-runner Vanessa Rousso, whom he called one of the strongest players in Big Brother history. 

"I had to!" Moses said. "I mean, it's weird ... Big Brother U.S. has never seen a big backstab on finale night."

Rousso's loss was shocking to a lot of viewers. Host Julie Chen had even pegged Rousso to win when ET chatted with her earlier this summer. 

"That actually makes me so happy that Julie Chen pegged me to win!" Rousso beamed after the show. "I'm a huge Julie Chen fan. She's hard to read... so, I never knew. Like, does Julie not like me?"

Speaking of Chen, we had all the Big Brother 17 houseguests deliver their best "Chenbot" impressions after the finale. Check them out right here: 

Even though she lost, Rousso has no hard feelings. She ran up to Moses in the backyard and gave him a big bear hug when she saw him in the Big Brother backyard after the finale.

WATCH: Julie Chen Looks Back at Her Big Brother Fashions: "There Have Been Many Mistakes"

"I'm OK with that," Rousso said. "It wasn't meant to be for me. It was meant to be for Steve, and he's a good kid. You know, he's a very good kid and he's a huge fan of the game." 

Liz Nolan was also OK with Moses' win. By evicting Rousso, he guaranteed Nolan a slot in the final two -- and $50,000. While Moses says he's not making any splurges with his winnings, Nolan already has big plans for hers.

"I can't believe this is happening!" Nolan gushed. "I want to take a very nice vacation. I'm going to treat [my twin sister] Julia and [my boyfriend] Austin ... I also still live at home, so I'm going to rent an apartment ... maybe I'll move here [to L.A.]. Who knows?" 

"I can't even breathe right now," Nolan continued. "I did not know that Steve was going to take me ... he really surprised me, to say the least." 

WATCH: Jeff Probst and Julie Chen: Why Survivor and Big Brother Are Better for Finding Love Than The Bachelor

Moses surprised a lot of people. Both Nolan's boyfriend, Austin Matelson, and James Huling told ET "the boy became a man" after the show. 

But chances of us ever seeing that man playing the game again are slim. Out of all the houseguests, Moses is the only one who told ET he will never do Big Brother again. 

"So happy I had this experience, meant the world to me," Moses said. "I am D-U-N-N. Done." 

Now that the season is done, too, relive it a little by watching Julie Chen give her rapid-fire opinions on the season 17 houseguests in the video below.