I think having a job affects my sleep. I have to get up at 3:30, leave the house at 5:00, and don't get home many days until 7:00. I try to be in bed by 9:30 latest, but that's only 6 hours of sleep. I just can't make myself get home and go to bed in half an hour, which is what it would take to get 8 hours of sleep.
Even when I drive I get up at 4:30 so that's not a big help. At least I get home earlier, but then I have to spend an hour or so lifting weights or doing yoga (yogging) or both.