Lindsay: "I've Grown Up Very Fast"

After a tumultuous 2007, Lindsay Lohan says she's finally at peace with herself.

"I think everybody should be just who they are and I am what I am," Lindsay tells Entertainment Tonight. "I've been doing this for so long and I've grown up very fast."

A former child star and now 21 years old, the starlet has lived quite a different, not to mention wild, lifestyle from the get-go than peers her age, which Lindsay admits she's finally learned the hard way she had rectify.

"I have different responsibilities than (other) people have at my age and it's taken me time to recognize that," Lindsay says. "I've gone through the phases that I've had to go through, so now I'm growing up and hopefully people are growing with me. I think it's an important message to send, instead of trying to be someone else."

With a slew of movie projects lined up and a "very therapeutic" third album in the works, life appears to be back on track for the redhead.

And just how changed is she? Lindsay plans on traveling to Africa to bring vaccines to the poor.

For more on Lindsay, tune in to ET tonight!