Washington, Dec 2 Popstar Britney Spears has said that the ups and downs of her life have made her more cautious, insisting that she now goes through life like a 'karate kid'.

In a candid MTV documentary, the 'Hit Me Baby One More Time' hitmaker revealed that after her trust was battered in the past she has now become protective about herself.

"I've been through a lot this year, actually the last two or three years and my trust has really been battered. I've definitely grown up, big time. I'm very weary of a lot of things. Very protective of myself," Contactmusic quoted Britney, as saying.

"You are guarded, you have to be that way, otherwise you get taken advantage of and get in situations like I did," she added.

Britney, who was featured in the documentary, which chronicled 60 days in her crazy life from the eve of her 2008 MTV Video Music Awards appearance to the middle of November (08), jokingly warned the people from her past from ruining her future.

"I had certain people in my life who were just bad people and I was very guarded at first but then I went to a point where I ended up letting them in, because I was lonely... and I really paid the consequences for that, Now I try to avoid situations from the past that may threaten me... I go through life like a karate kid," Britney said. (ANI)