Say, you had some problems with your fellow student(s)
and/or adviser, and you might be right (and they might be wrong). Does it matter to
make it crystal clear who was wrong and how wrong he or she was?
How about think it this way: no one is perfect, including a
professor.
(Ok, professor is never perfect. Does this help a bit?)
The important thing is whether or not you can go on
studying. If not, why not?
Also, remember to give him or her another chance.
Of course, you need to learn how to protect yourself,
including your research (data, records, etc.).
To forgive others is to unburden yourself with negative
feelings. Life is too short to be unhappy because someone else you don’t even
love!