When you're a kid/teen you don't know what may be an embarrassing photo or video. That's what being a kid/teen is about. The video you put online, discussing international politics with your impeccable 12 year-old wisdom, may have been the proudest day of your life.
You get older, you learn something of life, you realise that aged 12 you knew nothing, and you'd rather no-one was watching that video. It does not represent who you are now. What's wrong with wanting it gone?