That's very true too just takes a while to loosen tense muscles. I've noticed over time it makes me more aware of it when I'm tense. I'm starting yoga next week at the gym I go to so looking forward to that but also rather than getting annoyed and worked up about it try think more positive about it.
I'm having a bit of a hard time with focusing on breathing at the moment but I know I'll stop focusing on it after a while and my body will carry on doing it as it's designed to.