Sam Wells from Penkridge in Staffordshire, 48, was in a local supermarket in 2019 when she couldn't remember what she had gone in for.
The mum-of-two later developed a flicker in her eye and thought she might have had a mini stroke.
A concerned Wells went to the Royal Stoke University Hospital where she had an MRI, only to be told she had a mass of tissue on her brain.
Wells was soon diagnosed with something she hadn't originally anticipated – a grade three anaplastic astrocytoma, a type of rare, malignant brain tumour.
Her forgetfulness in the supermarket had in fact been a sign of brain cancer, with mental or behavioural changes like memory problems or changes in personality being a common symptom. Seizures, or fits, are also typically experienced.
She has since undergone serious treatments including surgery, 33 sessions of radiotherapy and a year of chemotherapy.
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“I had no idea what having a brain tumour meant," says Wells, who works for the NHS as a specialist nursery nurse.
"From that point everything was rushed. I wasn’t allowed to drive and had to call my husband and tell him the news."
Next thing she knew, she was having surgery where about 70% of the 'mass' was removed.
"I came out with 48 staples in my head, after which I was referred to an oncologist who confirmed the mass was cancer," Wells explains.
"Everyone copes differently when faced with something so huge. For me and my family, we know there may not be a long future, so we feel encouraged to live in the present."
"It’s not about creating bucket lists but about living in each moment we get to spend together."
Wells now has regular scans to monitor the remainder of the tumour and is on life-long anti-seizure medication.
But, despite what she's been through and her ongoing treatment, she is running a month-long marathon challenge this May in aid of Brain Tumour Research.
The Jog 26.2 Miles in May challenge, which is now in its third year, raises vital funds to help find a cure for brain tumours.
"I've got a decent walking pace but I'm not a runner. So far it's been good to get out and I've completed seven miles," says Wells.
"I have had amazing support from my teenage daughter, Megan, who is doing it with me alongside Woody, our Labrador-spaniel cross."
And Wells' determination hasn't gone unappreciated.
"We’re extremely grateful to Sam for sharing her story and signing up to support the charity with an epic month-long challenge," says Mel Tiley, community development manager at Brain Tumour Research.
"Her willingness to share her story to raise awareness will help us in our vision to find a cure for all types of brain tumours."
Brain Tumour Research funds vital sustainable research in the UK and influences the government and larger cancer charities nationally to invest more into the research of brain tumours, which kill more children and adults under the age of 40 than any other cancer.
You can donate to Wells' challenge here.
For more information, see our useful guide on brain tumour signs and symptoms, and more. While not all symptoms will be a sign of something serious, don't delay in speaking to your GP and ruling it out.
For support, you can contact The Brain Tumour Charity on 0808 800 0004.
Additional reporting SWNS.