A character in the movie who was actually really smart was Sean, a psychology teacher that agrees to give therapy sessions to Will. Sean was a very intelligent man, and very cultured. However, as bright as he was, he did have that "Southie" side similar to Will (somewhat colloquial) which was maybe a strategy to connect with Will. Something that I really liked was the contrast these two characters had. On one hand, Will was a genius, he was so knowledgeable about so many things like paintings and math, as well as pretty much any topic. And on the other hand, you had Sean, who even though wasn't as smart as will, he was sort of the "experience" aspect of life. I ask you, is knowledge more important than experience, or the other way around? This is shown where they are sitting in the park, and Sean calls Will out that even though Will could learn anything, he (at that point) could tell was true love was, or how it felt.
Another thing they had in common was an event that left a deep scar. For Sean, it was the death of his wife. For Will, it was his traumatic past while living in a foster home that left him somewhat vulnerable to other people. In the end of the movie, we see that they both leave Boston. Will goes "to see about a girl", and Sean was going to "buy another hand of cards". This was a moment they both left their comfort zones. Will would always push people away from him before they could so that he would get hurt. Sean had a mentality that his wife's death meant he couldn't move on. They both got over themselves.
Geeting over yourself connects with living a great life because it means you grew as a person. You achieved leaving your old, flawless self, and moved towards a new "you" not a perfect one, but much better than the previous one.