Without future planning, your wishes and preferences may not be carried out.
This could be because you are too ill to communicate, or because you have not made the proper legal arrangements.
Planning your future now, with the people in your life, will give you, your friends and family, more peace of mind. It also takes away the burden from family and friends of having to make decisions on your behalf.
Some of this may not relate to your current circumstances with Parkinson's. But it's important to know what arrangements and choices you may want to make in the future.
Remember that any decisions you make now can be updated whenever you want.