Herminia Ibarra, a professor at the London Business School, argues that job transitions \u2014 even exciting ones that you've chosen \u2014 can come with all kinds of unexpected emotions. Going from a job that is known and helped define your identity to a new position brings all kinds of challenges. Ibarra says that it's important to recognize how these changes are affecting you but to keep moving forward and even take the opportunity to reinvent yourself in your new role.