Counter intuitive to our culture, especially for men...vulnerability truly shows how strong someone can be. I have watched multiple TED talks, listened to speakers, and conversed with colleagues that all are saying the same message: being vulnerable leads to growth and greatness.
Pinpointing this phenomena has been eye-opening for me. Actual research has proven this connection and I will be shifting my mindset. But when you think about it, all the spiritual social teachings preach this - the last shall be first, treat others as you'd want to be treated, compassion and empathy. All of these concepts require vulnerability to enable the action of grace.
So when you are thinking, "I can't show my emotions, must be composed, strong, in-control," think of the pure experience you can have when not fighting but enabling your true self to others.