There was a decent explanation. Jane was taken to a secret research facility. Thor was only on Earth for his brother. Bro's before hoes ya dig? And Cap had his development. At the start of the film he was clearly awkward, felt out of place. But the new mission? That was what he needed. He's a soldier, a new mission made him feel worthwhile. And as the film progressed he became more confident. Culminating in Stark deferring to him in the battle and Cap giving out the orders, which was an excellent scene. All this **** was there. Again, do you people want it spoon fed to you or what?