I have always had a lot of fears. And since a young age I have been adamant about overcoming them. Not tiptoeing around them. Collecting them. Every time I collect one — every time I do the thing and survive it — something happens that still astounds me. How easy the second time is. How there is almost literally no stopping me. I always thought this was a mindset. It is not a mindset. It is fear extinction — and the female brain is specifically, hormonally primed for it at particular points in the cycle. Here is the science behind the thing that has helped me most.

There is a belief I held for most of my twenties that I no longer hold: that my brain had a ceiling. That the capacity I had was the capacity I got. I know now that this is not how the brain works. Neuroplasticity does not pause for difficult years. And in the female brain, it runs on a hormonal architecture that science is only beginning to take seriously.

I remember the first time I understood that my migraines had a pattern. Four months of tracking in a notes app, and the dates kept clustering around the same point in the month. Always the days just before my period. Nobody had told me this was a thing — not a doctor, not a neurologist, not the pharmacists I had consulted about whether I was taking too much ibuprofen. I had spent years treating each migraine as an isolated event. A failure of hydration. A punishment for the glass of wine. I had a list of suspected causes as long as my arm, and not one of them said: your estrogen just dropped and your trigeminal nerve is reacting. This is that explanation.

I spent the better part of my twenties thinking my body was unpredictable. One week sharp and focused, the next week foggy and tender — craving different food, needing more sleep, finding the same social situation that felt easy a fortnight ago now unexpectedly exhausting. It took years before I understood that what I was experiencing was not randomness. It was a programme. A 28-day biological programme that was running, flawlessly, every single month. Nobody gave me a map. So I built one.