How does someone leave a tampon in for so long?

So this is a serious question. This is why I’m so scared to wear tampons !! I read something that a girl left her tampon in for NINE DAYS and got TSS. & I know it’s a lot more common to forgot them in, how do you ladies forgot that you have a tampon in? Also this is a serious question, not trying to be ignorant. I’m just really curious. I know a lot of women who wear tampons and leave them in for a whole day sometimes or 12+ hours.