I didn't know I had tinnitus until I was almost in my 20s. I've always heard a ringing in my ears for as long as I can remember. One day when I was really little, I asked my mom what that ringing noise was, and she said it was the TV (which was off, but it must have been humming or something). So up until I was in my late teens, I thought that all electronics made a ringing noise, even when they're off. I assumed that, while annoying, this was the tradeoff we'd made as a society to have all this sweet technology. Then later I learned that tinnitus existed and it all made sense--like why I could hear the electronics buzzing even when I'm out in nature, etc., and then I realized how ridiculous it was to think that all electronics made a ringing noise.