Emma Stone "humiliated herself" when she had her hand print cemented in front of Grauman's Chinese Theatre.
The 28-year-old actress had "no idea" what was happening when she and her La La Land co-star, Ryan Gosling, were selected for the honour in December last year, because she thought the famous area in California was "full" and hers wouldn't actually be displayed.
However, when Emma found out the truth, she felt overwhelmed with emotion and was "humiliated" by her naivety.
Speaking on Jimmy Kimmel Live! on Monday (06.02.17), the flame-haired beauty said: "I had no idea what the hell was going on."
"[I thought], 'They've got all the hand and footprints. This is just a fun little celebration and they put it up in a museum somewhere.' I don't know why I thought this. It wasn't explained to me.
"So when we went I was like, 'This is gonna be a nostalgic celebration, we're gonna put our hands and feet in the cement and then they're gonna take it away and then they're gonna put it inside'. Then they were like, 'Here's your practice [cement slab] and then, when you get out there for the real one that stays out there, you'll know what to do.' And I was like, 'What do you mean stays out there!?' ... I had no idea!"
"[I] burst into tears and really humiliated myself."
And the Easy A star admitted "everyone" was surprised she was so clueless about the significance of the ceremony.
She explained: "Everyone was like, 'I don't understand how you didn't know that's what this is.'"
However, Emma has always wanted to have a cast made of her limbs on the Hollywood Walk of Fame, and had a memento made up when she visited the popular tourist site as a teenager, which she still owns.
She said: "You can go as a tourist and get your own hand print thing and I brought it home and had it in my bedroom."