Recently, a close friend of mine reached out, expressing his frustration over our mutual friend, who, for some time now, has ignored his calls and messages. We spoke at length, the conversation charged with emotion, and the underlying theme of our exchange led me to reflect deeply on the nature of friendships in adulthood. I have decided to share these reflections.

John and Darrel (not their real names) were two best friends whose bond went way back. They grew up together in the San Francisco Bay Area and attended UCSF. For most of their formative years, they were inseparable, celebrating small wins, picking each other up after setbacks, and navigating life side by side. Then life happened.

John landed a dream job with an oil servicing company and relocated to New York. Over time, his life took a different trajectory, one of financial success and social elevation. Expensive suits, exclusive clubs, jet-setting for work, and frequent overseas trips—his world expanded beyond what he and Darrel had once known.

At first, Darrel was genuinely happy for his friend. John remained supportive, gifting him with cash when necessary, helping with job applications, and even generously sponsoring Nosa’s wedding. But slowly, things began to change. The weekly phone calls that once anchored their friendship stopped. Text messages went unanswered for days, then weeks.

The conversations they had shared in the past grew increasingly strained, punctuated by awkward silences. Darrel, whose life had not undergone the same transformation, could not ignore the widening gap between them. He began to feel abandoned.

We’ve all witnessed a version of this story before. A colleague lands a lucrative job and suddenly becomes too busy to engage. A friend secures a prestigious position in government, and your calls no longer get returned. You ask yourself, “What did I do wrong?” The truth? Nothing went wrong. It’s simply a reflection of life itself, of the evolving nature of relationships and friendships.

Adult friendships, according to psychologists, are shaped by three key factors: proximity, energy, and timing.

Proximity, or the propinquity effect, refers to the way in which frequent, close interactions form the basis of strong relationships. People are more likely to form lasting friendships with those they encounter regularly, whether through work, shared living spaces, or social circles. Even in the digital age, where we connect across vast distances, the frequency of communication—whether in person, over the phone, or online—plays a crucial role in maintaining bonds.

Psychologists like Leon Festinger have studied this phenomenon, concluding that physical and emotional proximity fosters stronger, more resilient relationships.

Energy is another significant force that determines the strength of a friendship. Friendships thrive when both parties invest in each other, when there is mutual enthusiasm, shared interests, and a willingness to engage. A person who enjoys lively socializing will find greater fulfillment in the company of someone with a similar zest for life rather than a childhood friend who is a pastor and has chosen a more reserved, introspective path.

Timing is perhaps the most elusive factor. Life, in all its unpredictability, places us in different phases at various points in time. Sometimes, even the most promising connections are not meant to last simply because the timing is off. One person may be too focused on career ambitions to nurture the friendship, while the other may be navigating the complexities of a new relationship or undergoing a personal transformation. The timing of our lives, and where we are in our journeys, often dictates the relationships we keep.

We like to believe that friendships are anchored in deep emotional bonds, but the reality is that most adult relationships are, to some extent, transactional. The moment a friendship no longer serves a person’s needs or aligns with their current circumstances, it becomes difficult to maintain.

It might sound harsh, but if the roles were reversed, if Darrel had found himself in John’s position, he would likely have done the same. It’s not out of malice or disregard; it’s simply human nature.

At some point, we all wake up to the reality that some of our closest friends have drifted away, often without explanation and without closure. As painful as it may be, we must come to terms with the fact that, over time, people grow, change, and sometimes outgrow each other. And inevitably, we too will distance ourselves from people who no longer align with our present or future. It is not done out of spite, but rather out of necessity—because life moves on, and so must we.

The only constant in life is change. People leave. Friends become strangers. Lovers transform into friends. Colleagues drift apart as they pursue different goals. Some leave in search of better opportunities, while others, perhaps, find new interests or simply grow tired of the same old routine. It’s not personal; it’s just life. Life moves in seasons, and seasons inevitably change.

The sooner we accept this reality, the easier it becomes to navigate life without bitterness. Instead of mourning the loss of friendships that fade, we should cherish those that endure, all the while embracing the inevitable transience of human connection. After all, in the grand scheme of things, nothing lasts forever, except change itself.

So let go of what no longer serves you. Accept the ebb and flow of life. And when a friendship vanishes, remember: it’s not the end of the world; it’s simply another season of life passing.

Osmund Agbo is a pulmonary physician.