This aspect probably is a strain on your relationship. You have trouble with each other because your partner always pushes for openness, while you always want to stay closed, in self-protection mode. While they might be right -- you'd do better to learn that vulnerability doesn't have to hurt, and exuberance can be a wonderful, joyous mode of self-expression -- any pressure they put on you is likely to push you even further into your shell!
Their independence and flamboyance could actually get on your nerves and cause you to cling even more to your quiet, held-back ways. You two behave very differently, that's for sure. Your partner tends to be like an open book, ready to talk about their feelings, their hopes and fears, to anyone who'll listen. You, on the other hand, are quite the opposite -- not opening up even when encouraged. Well, has either of you ever heard the phrase 'happy medium'? Get acquainted with it! If you can blend your individual approaches to life, you'll both probably be a lot happier. Knowing when it's right to stay cool and calm is definitely a gift, but knowing that it's okay to cut loose once in a while and really express yourself is perhaps an even bigger one. Given time, you probably both start to blend your styles without even realizing it. You could have a very good effect on each other over time.