I use to say that it takes about 5 minutes to explain how Scrum works, but my experience is that it takes between 3-6 month to learn to work with it.
It is a mindset change and it require that you understand why you do the different things and what you are trying to achieve.
Most people are lazy and will resist change, I grabbed the picture below from this blog
It is a pretty good description of what most teams go through. They usually have the old way of working, i.e. water-fall model with Microsoft Project plans and a Project leader who execute the project...
In my experience the project leader often ask the developers and other involved parties what needs to be done, when it should be done and how long time it will take and then create and maintain a project-chart - in Scrum there is no project leader, but the team act as the project leader and the Product Owner (PO) act as the customer representive requesting work from the team in right priority.