For me throughout my life, it was the "forbidden fruit".
Whenever my dad would be pulling tubes to be tested on the living room set (I think it was a CTC-15), I wasn't allowed anywhere NEAR him. I remember sitting at the top of the steps peering inside and trying to see the magic within.
Then, when I was 7, I discovered tube radios. I still have my very first radio bought in October 1978 for $1 at an auction (A Motorola 65X12 I think), and then we went back in November and I bought another (Bendix 636D). I still have them both. Then it was on to TVs, I had a 24" Motorola B/W hi-fi console set in my bedroom that my parents hated....but I bought it for $5 at that auction months after. Used it for years.
Ever since I was a boy, I have wished, wanted, and hoped that someone would teach me how to repair radios and TVs. Every old tech I ran across told me that I shouldn't fool with things like that, and cast an aura of some kind of magic dangerous voodoo over the whole thing. Loved the stuff all my life, but never learned how to fix anything.
It wasn't until my mid 20s that I got bold enough, and sick and tired enough of waiting for someone to show me the ropes that I said, "screw it, nobody wants to teach me, I'll figure it out myself". Managed to come this far....not perfect, but I'm pleased with my progress and I learn new things all the time.
One day, maybe I'll find a little boy just like I was, with that starry eyed look of tubes glowing, and I'll take him under my wing and give him the teacher I never had
My kids are too busy playing PS4 lately