Its absolutely terrifying to let someone in. Let them see the darkest corners of your soul, the reasons why you cry and why they make you happy. Its absolutely terrifying because they might run away with your secrets and never give them back.
Often our armor isn't needed. But sometimes it is. And it's far better to use past hurts as armor than to let them shackle us. As long as we remember to let that armor down and just let things go when it's not needed.