Part of promoting her new movie, "Georgia Rule," in which she stars alongside Jane Fonda, Lindsay Lohan made an appearance on David Letterman’s "Late Show" and said she learned a lot from Jane Fonda, while mentioning she was "immature" and "irresponsible" on the movie set several times.

"I was out too late a few of the times. I had a boyfriend. I was fighting with him," the 20-year-old actress told David Letterman Wednesday. "I was very immature. It was very irresponsible. And I understand that."

Speaking of Jane Fonda, who plays her grandmother in the movie, Lohan said : "She's incredible. She taught me a lot of things actually, (such as) being on time."

Back in 2006, Fonda publicly criticized Lohan’s attitude after she failed to make it on time for work, delaying the shooting.

"It’s hard after a while to party very hard and work very hard. She'll learn that," Fonda told Access Hollywood.

"She’s so alone out there in the world in terms of structure and people to nurture her. She is so talented. Oh my gosh, she can access emotion like nothing ... And she just makes me cry. I just want to take her in my arms and hold her until she’s grown up."

When she was asked by Letterman whether she thought about the paparazzi and endless gossip about her personal life, when she was a little girl who wanted to become an actress, Lohan said she didn’t quite consider all that at 7-years-old.

"It wasn't as terrible then as it can get now," she added.

However, referring to her current life, the young starlet said she’s pleased and she’s having a good time.

"It's good. I'm having a great time," said Lohan. "I'm feeling good. I'm probably in one of the best places in my life. You have to be able to live your life and do what you want."

Also, the actress, who has been both a friend and rival to the hotel heiress, Paris Hilton0 does not believe her punishment for driving with a suspended license is fair.

When questioned about the matter, Lindsay said: "It's terrible."