Nine years ago, I entered public health with a simple idea: prevent disease. I thought the work was primarily scientific. You study the pathogen, you understand transmission, you design the intervention, you implement it. The disease goes away.
What I did not understand was that public health is not primarily a scientific problem. It is a human one.
Science tells you what to do. Public health is the discipline of figuring out how to actually do it, in the presence of limited resources, competing priorities, fragile institutions, and communities with histories that shape how they receive or resist any intervention you design.
Over nine years, I have worked across multiple Nigerian states. Polio eradication campaigns in the northwest and northeast. Disease surveillance systems in states with some of the most challenging security and infrastructure conditions on the continent. Immunisation programme support. Monitoring and evaluation for health system initiatives. Each assignment taught me something the previous one had not.
This series is an attempt to share nine of those lessons, one for each year. Not as definitive truths, but as honest reflections from someone still learning.
The lesson that underpins all the others is this: the gap between knowing what good public health looks like and actually delivering it is enormous. It is filled with funding cycles, political transitions, staff rotations, community mistrust, supply chain failures, and coordination failures between well-meaning organisations. Navigating that gap is the real work.
If you are entering public health, or if you are mid-career and wondering why the system feels so resistant to change, I hope these lessons offer something useful. Not comfort, necessarily. Clarity, perhaps. And the knowledge that the difficulty you are experiencing is not a sign that you are doing it wrong. It is the nature of the work.