For a man who has spent his life quickly turning his decisions into action I would actually expect that he is surprised at the difficulty of dealing with the bureauracy.
I also think he must be surprised that the good things he’s trying to do...i.e. better vetting of immigrants that will keep us all safe, are oppossed by so many people. I know I don’t understand it. I think some of these people would rather have ISIS running the country.
Massive projects involve navigating (and sometimes creating) massive bureaucracy. Can you imagine the systems and processes needed for building a skyscraper? Or the governmental bureaucracy for building said skyscraper in downtown Manhattan? Or in dealing with myriad foreign governments?
Since Trump isn’t much of a political animal, I could see how he would be surprised by how bitterly partisan some of his former friends in the Dem party are towards him, but I imagine he’s a quick learner and he knows how to fight.