Jennifer Aniston reflects on Last Episode of 'The Ellen DeGeneres Show'

Jennifer Aniston is sharing her experience of being on the final episode of The Ellen DeGeneres Show in her latest interview.

The Friends alum, who was the first guest on the show when it debuted in 2003, appeared on Ellen’s show multiple times throughout its 19-season run and returned for the final episode, which was taped on April 28 and aired nearly a month later on May 26.

Now, recently in an exclusive interview with PEOPLE, Aniston shared her special moments of the show.

"It was so bizarrely sad. "I have to say, because I did the show at the beginning of the year and I was really emotional then, and I kind of was like, 'I can't do that on the last show. I'm going to really lose it.'"

During the series finale, Aniston also gifted DeGeneres a "Thanks for the Memories" welcome mat, in a nod to the mat she gave the host during their first on-air conversation years ago.

And even though it's been a few weeks since DeGeneres has wrapped the series, Aniston says she still hasn't processed how she'll never be a guest on the talk show again.

"I still can't wrap my head around [the fact] that that's it," she says. "It's not going to be there anymore, because it was such a staple."

"Even though the world was there before Ellen and now it'll be there after, she was such a source of entertainment and love and joy and laughter for people. It's sad," she adds. "I don't understand what's going to fill it."