Immersion

As a shoot off from another thread I've been following lately. Someone has bought up the question of immersing yourself into a character in order to give an honest portrayal of that character. So I pose the question to people. Are there any characters you have had trouble getting in and out of? Any general comments on the topic? What do you do to try and get into those incredibly surreal characters or characters that have absolutely nothing to do with you personally? My own 2cents worth that hasn't been mentioned in another thread: Recently I've been given the opportunity to bring to life a charcter that has been floating around my mind for about 12 months now. Tarsha - muse and story keeper. She is about 7yrs old in appearance and sometimes in her actions she is childlike. The truth being she doesn't actually exist except in other peoples minds. Strange concept but fun to portray. I've been using alot of observation just going out - freo mainly - to the park and town and observing children and there behaviours and responses to everything. Been watching family movies of when I was younger (which has been amusing) back when the world was big and exciting and everything was fun and laughable. After drama classes I sometimes find myself sitting in a serious subject - history so to say - laughing, bouncing and making overlarge gestures when I talk. I find it hard to step out of Tarsha's character in such a short space of time - 2min walk from one class to another - and after 2hrs being her it's too much fun to leave her there in the drama room. I guess my most recent and ongoing experience. Thankfully not a bad or psycotic character just one thats hard to break. I know that Tarsha will stick around in my mind until I get a chance to put her full story on paper. But until then. . .I am curious as to others comments and experiences.