We all have our preferred role, as our brains are wired to prefer certain states. Add, to this, habitual patterning, and we become rather set in our ways. This is especially true after the age of 25, due to the developmental cycles our brains go through.
For some, this persona is a quick-thinking, anxious creature who is good at their job, but unable to accept criticisms. For others, the adopted mindset is slow to respond, quick to notice, and a bit of an isolationist who would really just be left at home. The list of potential personalities does go on from there, but these examples should provide something for your mind to latch on to.
If you have issues with getting stuck, I would recommend a minor exercise. It doesn't require a whole lot of skill or magical ability, as you're not going to be communing with any deific spirit, but it does require some patience and diligence.
At the end of each day, make a list of 5 people you've interacted with. When you've got your list, start at the top and try to become them....contemplate their thoughts, worries, concerns, and triumphs, that day. Consider what was important to them, and why they responded the way they did. Do so for a minute or two, then move on to the next.
At first, your preconceptions will likely cause you to insert your beliefs about them, rather than what is authentically their persona, but over time you'll learn to connect. Doing so will help you to shift from one mindset to the next, making it easier for you to don new mental clothes in the future.
Have fun with it. Its a strange exercise, but it does work.