Spanking has had a secret thrill for me going back almost, but not quite, as far as I can remember.
My earliest kinky memory is of being very small, just five or six, right at the start of primary school. Myself and two other small boys standing in the playground, with a ring of older girls (maybe 8 or 9?) dancing around us in a circle holding hands, chanting - in a "ner-ner-ne-ner-ner" type way - "Girls get the slip-per, boys get the caaa-aaane", before breaking away and running off giggling.
That's probably the first time I ever felt that scared-yet-excited tingle in my tummy & bottom.
I also remember feeling a bit put out by learning this "fact", but then I thought about it and conceded that it made sense given that boys were caned on their trousers whereas girls had their skirts lifted and were dealt with on their knickers. (How I "knew" this I have absolutely no idea and would love to know - possibly from children's comics of the day?)
Also, my first primary school Headmaster carried his cane with him wherever he went, and the sight of it had a powerful effect on me. We were guaranteed to see it every morning as, unless it was absolutely pouring with rain, registration was taken in the playground: we'd all line up alphabetically in seven columns with our class teachers at the head of each line, with the Headmaster standing behind them, holding his cane as always. Sadly my surname is in the second half of the alphabet; had it been "Abbott" I expect I would have ended up even kinkier than I am!
A year or two later, I accidentally discovered masturbation (which I might write about in the appropriate thread), and was immediately worried that I might get spanked for doing it. I got semi-regular hand spankings from my father anyway, which I absolutely hated, they gave me no pleasure at all... but for some reason that I didn't understand at the time, I found the terror that I might be spanked for doing this new secret thing I'd found, only made the excitement more intense... and lo! a spanko was born. :-)