Clarke, 22, beat out veteran Benjamin "Coach" Wade, 39, veteran Oscar "Ozzy" Lusth, 30, Albert Destrade, 26, and Rick Nelson, 51, on the CBS hit show's 23rd season.
"I feel awesome!" Clarke told PEOPLE on Monday, the day after the show's winner was announced.
"I had a good idea I was going to win. But I didn't want to be too blasé about it because you never know. Then I found myself getting more and more nervous leading up to it – but then I won."
"This is all so overwhelming," she adds. "I still haven't seen the show yet, so I'm sure when I see it on TV, it will feel so much more real."
Clarke also spoke about how she plans to celebrate – and spend her prize money:
What do you plan to do with the prize?
I'm in medical school, so I have a lot of bills to pay. I opened up the mini-bar this morning [at my hotel] and bought a very expensive Diet Coke, so I'm well on my way to the land of extravagance.
Aside from winning, what the most memorable moment of the experience for you?
The final challenge. Ozzy is in his own right, a challenge beast. He told me that morning, "I voted you out." If I didn't win, that was it for me. There was no redemption at that point. We were really exhausted.
Are there any moments that you're not so proud of?
Well, I watched myself cry, which was really difficult, but I think people enjoyed seeing me show some vulnerability and exposing myself a little more. But I seemed pretty hypocritical ... complaining about Ozzy calling me a pretentious brat, but I was going around calling him an a––e.
What terms are you and Ozzy on now?
I've seen Ozzy quite a bit. We're friends now. Everything's fine. On the island, we talked and agreed that part of the reason we didn't get along was because we were too similar and we were both very hard-headed. We're both very competitive and confident, and I think that when you put together two people like that, they clash. Survivor isn't real life. It's some massive board game.
What was the biggest thing you learned about yourself from this whole experience?
Oh, I need a cliché for this one. Every cliché will work here. I went on the show not expecting to learn anything. I went on the show because I was a fan of Survivor and I wanted to win the game. But [in the end], I've never felt such extreme emotions in my life. It's like high school sports. I've learned a lot about how far I can push myself. I learned a lot, too, about my weaknesses, and how I make first impressions.
How do you plan to celebrate?
I'm going to go skiing for Christmas. It's been about six months of celebrations, and I think it'll be kind of nice to have a Wednesday without Survivor. I'm just trying to take it all in. I have to go back to medical school. I actually flew in and took my exams in the hotel.