Most assets require maintenance. Skills decay without practice, fitness disappears within months of stopping, knowledge expires. There is one exception I can think of, which is reputation. A reputation, once genuinely earned, accumulates quietly while you do nothing at all. The whole thing runs on its own, requiring no upkeep beyond continuing to behave as you did when you built it.

The reason it works this way is that professional life is a repeated game with a surprisingly small cast. The field you work in is probably a few hundred people who matter, and over thirty years you will encounter the same names again and again in different configurations: the PhD student becomes the research director, the junior engineer ends up running the division, the person you declined to help turns out to chair the panel. Anyone who behaves as though each interaction is a one-off transaction is playing a fundamentally different game from everyone around them.

The asymmetry is what makes this worth taking seriously. Building takes decades of unremarkable, consistent behaviour: doing what you said, giving credit where it belongs, declining to take the small advantage available. Destruction takes an afternoon. One badly handled authorship dispute, one piece of credit quietly taken, one promise broken at a moment when it was inconvenient to keep. People remember those with a clarity they never apply to your good years, and they tell others. So, as a reflection for today: if the people you worked with ten years ago were asked about you now, what would they say? And is it what you would want?