"Narcissist" is a popular term of day-to-day speech. It's not only used to describe people with an inflated sense of self or entitlement, but has become interchangeable, to some extent, with "jerk" and some of its synonyms. In its daily usage, the meaning of "narcissist" can get lost, however, leave it to Ted-Ed to describe it in an interesting, clear and fun way.
With that said, relationships with narcissists or people who have narcissistic tendencies can be challenging to navigate. Seeking therapy in order to help work through these difficult relationships can be extremely meaningful, in order to gain strength, insight, support, as well as tools.