It hits me out of the blue. I don't know what makes it happen or why. I could be watching a movie, reading a book or out shopping and suddenly it's there again.
It doesn't happen very often, and it happens less now than it did at the start, but when it comes, it floors me.
I can't eat and I can't sleep. My skin tingles and no matter how much water I drink, my mouth remains dry. I might get a pain in my chest or my leg and then the pain magnifies and transfers to other parts of my body.
I know it's all in my head but then I think what if it isn't, what if it's back. That sneaky, insidious little cancer cell is nowhere, yet everywhere.
I was told this would happen but knowing doesn't make it any easier. They are called the 'wobbly moments' and they happen to most people who are cancer survivors. I'm one of those people.
"What are my chances of recurrence?" I asked my oncologist last year. He didn't hesitate.
"Twenty-five per cent."
He wasn't talking about cancer in my second breast but a recurrence of my original breast cancer. In other words, metastatic breast cancer to my liver or bones or brain. Secondary cancer that is incurable.
"Twenty-five per cent is quite high," I replied.
"What you need to concentrate on is the 75pc bit and go out and live your life," he replied.
He's right of course and, for the main, I do just that. But sometimes I hit a 'wobbly moment' and I'm right back where I don't feel safe or secure and the future is something that cannot be imagined.
I mentioned my 'wobbly moments' to someone recently and they said I should treat cancer as "a gift". I'm not ashamed to say that I wanted to punch their lights out and I used the F word to full effect. Cancer is not a gift. Cancer wrecks your head.
Sometimes I wish for my life before I was diagnosed with breast cancer. That life when I didn't have to think of what might happen if it comes back. That life where I wasn't on first name terms with an oncologist or where six-monthly check-ups weren't part and parcel of my life.
But then, after a day or two, I get over it. I look at my family and think I want to be around for you. I have coffee with Maggie, Josie and Patsy and they let me wallow before giving me some belly laughs and making me forget.
The wobbly moment passes and I think to myself 'I'm here'.
And it's alright again.