Copyright

There are a lot more meanings and views than I ever imagined on ideas of copyright. I thought that copying a simple idea from someone else, such as copying unintentionally the way one speaks or makes hand gestures, could be one of many piracy. Well, this example wouldn't really be considered as theft or violation of copyright, however there could still be an aspect of that depending on how one perceives it. Am I always stealing someone else's ideas, words, gestures, etc. to incorporate them into mine? As I read the Free Culture by Lawrence Lessig, I'm keep thinking about whether I am using other's stuffs again or not in every moment. Well... not every minute but often. When I am reading the book, I look up the dictionaries a lot since there are so many words that are new to me. And sometimes, I find some very useful or just very attractive. So I remember them and try to use them later whenever I am talking to someone or writing an essay. Here, I was just trying to learn English. But can it be also considered as using other person's very own word? I just thought this way for once while I was reading Lessig's opinions. I think I don't need to go that deep. Right?