I used to sloppy throw around the title "friend," designating it to essentially anyone that I had ever had a pleasant encounter with. Whether it was someone I had worked on a project with two years ago, or even someone I had briefly encountered in the lunch line, they were my "friend."

All throughout high school, I was always surrounded by people who I considered friends; we would laugh and study together, go on day trips, and share frivolous tidbits of our days with each other. It was enjoyable and lighthearted, and in these experiences I found individuals who I was comfortable with and groups that I valued for their unique dynamics. However, it wasn't until my senior year that I started recognizing the blurred line between familiarity and genuine companionship: which relationships were just for fun? which relationships were strictly academically related? which relationships had the kind of intimacy that would endure even after we would go our separate ways during college?

During this last year of high school, I made a new friend -- someone who I had known for years, yet never quite got the opportunity to talk with. He strictly defined four facets of friendship, as outlined below.

Sacrifice

Friends sacrifice for one another. This does not necessarily indicate grandiose sacrifices that jeopardize careers or foundational values, but rather small acts of simple selflessness or commitment. This can mean carving out time from a busy schedule to talk, or even simply compromising by agreeing to carpool.

Humor

As frivolous as it might seem, humor is extremely important in fostering intimate relationships. It makes experiences enjoyable, and allows individuals to bond by laughing over shared experiences. Even when someone is feeling down, sometimes laughter just might be the best medicine.

Vulnerability

A friend is someone you can confide in. It is someone who you trust knowing your greatest fears and insecurities, someone who listens with good intent and concern. Anyone can laugh at your jokes and enjoy the good times with you, but only a special few will stay when skies are grey. In fact, true friends are those who want to stay and pick you back up.

Mutual Appreciation

In order for a friendship to exist, two individuals must mutually agree that the relationship is valuable. Acts of appreciation are simply another way to communicate this agreement, and creates security between two individuals.

Good friendship are one of the greatest blessings we experience during our lifetimes. However, as we grow older, we accumulate more responsibilities and realize the limited amount of time we have for maintaining friendships. As such, I encourage you to critically think about who in your life fulfills your criteria for friendship and build from that strong foundation.