That statement is false.
On average, people obtain a sense of humbleness as we got more mature.
This is also true among artists. Younger/new artists tend to feel that they're artworks are a break through and should be used as a new standard even if their skill is still unpolished.
Answer: The following is one of the friendship rules identified in a study by communication researchers Michael Argyle and Monika Henderson:
B. Don't be jealous of your friend's other friends.
Explanation:
Michael Argyle and Monika Henderson conducted a study and were able to identify rules for successful friendship, one of those rules was, "Don't be jealous of your friend's other friends."
In "The Rules of Friendship" Journal of Social and Personal Relationships (1984), Argyle and Henderson found some of the following 'rules', "...“should not be jealous of other’s relationships,” “help in time of need,” “respect the friend’s privacy,” “confide in each other,” and “stand up for the other person in their absence."