I know usually the question is always answered with, "people in their 30s should get 8 hours of sleep". So I have, and I'm still tired throughout the day and the morning I feel like I've been in a coma for 3 months, like it takes me 2 hours to get it in 5th gear.

I was talking to a buddy around the same age as me and he said he could only sleep for 6 hours and that after 6 hours is bad for him.

Am I doing harm to myself from sleeping for 8 hours?