It's so difficult to try to have a relationship with someone who minimizes all of your needs and exaggerates all of their own.

I work with someone like that
Plus, it's always someone else's fault

A partner that is selfish shouldn't be in a relationship,if he/she doesn't know that one of the fundamentals of a successful partnership is tovoffer concessions.

Don't. When you recognize such a person, remain polite and courteous (of course) but do not seek to engage beyond what is necessary.

I avoid people like that in general

Not difficult, impossible.

Why have it at all?

Sounds like every president of the USA

Damn skippy it is