Cast member Drew Barrymore poses at the premiere of the movie "He's Just Not That Into You" at the Grauman's Chinese Theatre in Hollywood, California February 2, 2009. [Agencies]

Latest Photos: Aniston, Barrymore  at premiere of "He's Just Not That Into You" in Hollywood

Drew Barrymore believes people are just "fields of energy".

The 'He's Just Not That Into You' actress insists everyone has the choice whether they are happy or sad.

She said: "I like projecting positivity. I believe that we are all fields of energy and you have the choice whether to be a positive or negative field of energy. I know that sounds hippie-ish but it's what I believe fundamentally. So you could be a bag of toxicity, or you could be a happy, good person that spreads joy. I believe in spreading joy."

The 33-year-old star - who completed two stints in rehab during her teenage years and has been divorced twice - insists she is living proof tough times can make people stronger.

She added to People magazine: "Everybody goes through hardships and it's your choice how to deal with them. Your choice should be to progress and to evolve, and to handle things with some level of graciousness.

"Yeah, life is hard sometimes - but I think you probably have to just realise, you know, that someone is probably experiencing something more difficult and to please work past it as expediently as possible."