When we talk about an overblown sense of one's qualifications, we usually deal with idiotic vanity, ridiculous selfishness, absurb narcism, somophoric overconfidence, ignorant bigheadedness, vaniglory and other simile. All of these pertain to foolish pride.
We don't want to be around people with this sickening attitude.
Self-absorption or being a swagger is not good especially when it comes to friendship and breathtaking romance. Foolish pride destroys the camaraderie killing the passion of any beautiful relationship.
Hardly can we find individuals who easily forget silly egotism. Harebrained immodesty is one of the most difficult negative behaviours and we don't like to face them in a way that will ruin our day. So the only means to evade such persons is to ignore them as if they don't exist. Surely, they will get the message.