These types of friendships (based on pure love of the other person for their lovable character) are likely to be rare, since such people are few. Further, they need time as well, to grow accustomed to each other before they have shared their salt as often as it says, and they cannot accept each other or be friends until each appears lovable to the other and gains the other’s confidence. Those who are quick to treat each other in friendly ways wish to be friends, but are not friends, unless they are also lovable, and know this. For though the wish for friendship comes quickly, friendship does not. – Aristotle
Aristotle outlines three types of relationships that people might consider friendship – those that are based on usefulness, pleasure, or those based purely on virtue. Friendships based on utility/usefulness are prone to decay rapidly once the utility of the relationship no longer exists. Friendships based on pleasure (for example, someone who makes you laugh or that you have a good time with) are also prone to decay, since human emotions and whims and what entertains us is often changing, and much like friends based on utility, once the pleasure is gone, we may find that we actually have little in common with the other person.
In contrast, friendships based on mutual respect and admiration are the most enduring. Consequently, they may take much longer to form, but once they are formed, they do not so easily decay. These observations from antiquity are still easily applicable today, with the lesson being that we should endeavor to form bonds of like-minded people whom we trust and whom we love by sheer nature of who they are and their character. These friendships will stand the test of time. It also means that introspectively we should work to be lovable and to develop a character that is worthy of others’ love, admiration, and respect. Surface level affections based upon humor, attractiveness, and what we can do for others, is much more fleeting.