Thankfully we are at a time when women's bodies and their experiences are much better understood and talked about, but it wasn't always like that! I'm only in my 40s but I have one I'd like to share:
Ovulation pain. Ever since my cycles began, I have had quite severe ovulation pain. Even today when I'm in peri, the pain can be so sharp that it takes my breath away, or I have to limp when I walk to take the pressure of it. But I remember when I was younger telling people about it, and how I could tell which ovary was ovulating because of the pain, and was outright told "no thats not possible, ovulation pain isn't a thing". It was only in my 30s that I discovered that in Germany they had always known about ovulation pain, and called it mittelschmerz, 'middle pain' because it happens in the middle of a cycle!
I wondered if any other women have experienced being gaslit about something that turned out to be a totally normal for a female body?