All collectors have stories. Mine was a present from a boyfriend. He didn't know what to bring back from a visit to his sister in Guernsey so he went to the post office and bought the stamps from a halfpenny to a pound. Fast forward about 5 years.
I'm married, to someone else, of course.
My father said, casually, as was his style, "Have you checked the perfs on that 10/-?"
Me, "It won't be the expensive variety. It never is"
But I checked it anyway.
You know the rest - it was SG27a - the expensive variety. It was UMM and I didn't particularly collect mint stamps of any sort.
I've just checked current prices and I did well to sell it as I acquired two nice King Edward VII high values in exchange!