I've been into knives since I was a todler, parents weren't too keen on letting their kid play with blades though.

But I managed to get my hands on some cheepo folding lockblades and a couple pilfered kitchen knives that I treasured when I was around 7 yrs old.
Around the age of 11 I started buying kitchen knives from Goodwill for pocket change. I'd make sheathes out of cardboard and duck tape, then take them out into the woods to play around at bushcraft.
Was allowed to pick out my first pocket knife worth over $20 when I was 12. Being 12 I of course picked a slick little taylor-seto balisong, and I LOVED that thing! EDC'd it til it was stollen when I was 19.
So I was kind of allowed to have knives at the age of 12, but then at 13 or 14 I got into knife throwing, and one night while my parents were gone I decided to take steak knives and throw them into the back side of the kitchen cupboards.... my father was NOT amused! He confiscated my knives and put them away until I was "more mature"
That didn't slow down my collecting at all though, I was already into scrimping and saving for knives, but when I turned 14 I started working..... which gave me the funds to buy more knives. I hit up the flea-markets for cheep blades of all styles and sizes. When my Dad would inevitably catch me with a new knife he would add it to his growing collection of confiscated blades... haha... We camped and hiked alot though, and he would always let me pick out one or two blades to take with and use for the weekend, so it was kinda fun. He was into shooting and the outdoors and liked knives but never had the fever for them like I did.
By the time I was 15 my parents gave up and just let me go wild with my knife enthusiasm. But by then they simply weren't around much anyway, (I pretty much raised myself from then on), so my situation wasn't exactly tipical.
Now I have kids of my own, and will have to figure out the propper ages for me to be ok with letting them have knives. (if they even show any interest)
I think ultimately it doesn't so much come down to age, but rather individual personality and responsibility level of the kid. It's too bad that your friends parents may be afraid of knives, but maybe you could help change their view on the matter by showing them how YOU can own and use them responsibly, and how they are useful tools and not just flashy weapons.
-Bry
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