First sexual memory

I thought I'd share my first sexual memory, not my first sexual encounter or contact but my first memory of feeling sexual or aroused.

I was probably about six or seven, though I can't really remember, I was in bed and had been asleep but awoke for some reason.
Touching myself it somehow felt good and I slipped my pyjama trousers off, after a minute or two I felt I wanted to go for a pee and feeling how I did, thought it would be good to go without my trousers on. I slipped out of bed and across the landing, I had something of an erection and remember thinking it must be, perhaps because of the cold or just that it felt “naughty” to be naked from the waist down, I somehow managed to pee and then headed back to my room still sporting my little stiffy, as I neared my parents room I saw the door was open and my mum was stood watching me, “you alright darling?” She asked
“Uhh yes, just needed a wee” I replied hurrying past her
“Where are your pyjama bottoms?”
“Oh I was hot” I said, a bit flustered, knowing that she was looking at my erect little penis
She smiled sweetly at me as I closed the bedroom door
I jumped into bed and laid on my stomach rubbing myself against the bedsheets until I fell asleep.
I'm not sure why this memory sticks so vividly in my mind? Perhaps because I was caught by my mother and quite mortified at the time, or maybe because it was one of the first times I was naked in that way, not in “private” or in the bathroom etc?

This is something I've thought about and remembered many times so decided to write it down and share.
I'd be interested to know if others have similar memories?