I wouldn't give a damn. I was picked on a bit but not particularly badly, or for long. The thing is bullying can have different effects on people, depending on the severity, frequency, disposition of the victim, physical/psychological, how widespread it is, etc.
Teenagers in particular, in their mission to become adults, form opinions, gain acceptance from their peers, rebel against the man, attract the opposite sex and get a "status" of sorts. Some like to find niches to belong to, like the arty kids, the skateboarders, the athletes, the musical kids, the heavy metal fans, etc. but for most they simply are. And there's always a pecking order and it's very hard to break out of where you fit in that order once it's established. If a kid is the victim early on, they will remain so for the entirety of their school careers.
Kids bully other kids, but at teenage age, it can cause victims to grow up with severe depression, lack of confidence or self-esteem, loneliness and more. Some run away, move/change school, cut themselves, some kill themselves (or in America, they shoot other kids with Daddy's arsenal). As teens become young adults and they become more mature, bullying kinda grows out. There's little to none in most workplaces (good ones at any rate) and adults are much more confident anyway. But if it happens during those formative years, like 10-20ish, it can mess people up for life. For some, maybe the apology helps. It might not matter to you, maybe you were never bullied, or you're more thick skinned, but for some it can be traumatic.
The more of the following you meet, the less likely you ever knew bullying: white, straight, good looking, middle-class, Christian/no-particular-faith, male, slim, dark haired, good vision.