What's the Gap in the Curve?

In order to engage in something, for those of you all that are familiar with chemical reactions and stuff, there's this idea of an activation energy. This is the gap that we have to overcome in order to initiate the behavior. For our friends who say, oh, just put yourself out there, their gap is going to be like smaller, ok? That's why it feels easy to them. But what we face, in what they face, is a little bit different. So let's try to understand what are the components of this hump that we must go over.