Why is a dissertation difficult? Because you have not done this before. You have no practice.
There was a time you did not know how to speak, or walk. The practice you have done has launched you to mastery.
There is so much that you will gain by your practice. Remember that practice is not repetition alone. So much deserves the effort of try – fail – learn – improve – repeat.
Practice writing, literature searching, communicating, writing statistical code, and tweaking that laboratory experiment.
Practice saying no. Practice seeking advice. Practice acting outside of your comfort zone to make connections, seek clarity, pursue an idea, or give a presentation.
Practice identifying flaws in a publication. Practice incorporating the limitations in how you interpret research results. Practice the common tools of your discipline.
Practice your organization and management of your email.
Practice your confidence.
Even charisma itself can be learned, and improved, with practice.