ELI5, why is going to bed super late bad for you if you still get the same amount of sleep?

Question

I’ve always wondered this, espeically over summer break or for those who work later but why is going to bed late bad for you if you still get the perfect amount of sleep?

For example, last night I wen’t to bed at like 1:30 AM and woke up at 10:30 am, which is 9 hours? So if I’m getting required sleep, how is it bad for me?

In: 2565

Answer 1

Going to bed late being bad is assumed you will have to get up early like for work or when you have to get your kids up for school. But if you get at least 8 hours of sleep you are good.