Negative remarks.....

" Hm, I don't know", " I can't do". I heard these sentences every day. Why did people tend to use these sentences? It is like they aren't capable of doing something or they are not confident with themselves. I try to avoid these sentences and do what I have to do. I felt like sentences that we uttered will represent ourselves if we doesn't control it. Think before saying anything because sometimes, words can kills the owner.....