Maybe It's All Mental...

So, for the past 3 years worth of school, I've been getting up at 5:30 on days I have class. I've lived at home all 3 years. (And UTA's bus timings got better, and since have gotten progressively worse.) Sometimes its because of work at 7:45. Sometimes its because of 7:30 class. Other times, its just because UTA is run by pathetic bastards who don't care about Sandy-ans.

Anyhow, I've come to realize that if I get up at 5:30 and get ready, no matter how much sleep I got the night before, I'm always tired on the bus on the way to school. That, and I'm tired in class... both Anatomy (8:35 AM) and Physiology (9:40 AM).

Now, I'm kinda used to sleep. I took a 7:30 AM class my second semester (lived in the dorms), and so to get enough sleep and get up in time, I used to sleep around 10. That has continued since then... pretty much every night, bedtime is between 10 & 11 (unless I need to cram). So I'm usually getting 7 or so hours of sleep. Though there seems to be a night very early every semester that I'm up late for some reason, and it throws my sleep pattern off.

Anyhow, I digress. Back to the bus trip to the U. Like I said, if I get up at 5:30 (most of the time, I'm up a couple of minutes before my alarm goes off), I'm sleepy on the bus. Though I've come to realize (as of late) that if I stay in bed a bit longer (5:35 like today; 5:45 like sometime last week; 6:00 like the day I was planning on skipping class but ended up not), I'm not tired on the bus. And I'm more-or-less wide awake in both Anatomy & Physiology.

Why is this? Is it all in my head? Or does the extra time in bed (5 minutes to 30 minutes, whatever) really make that much of a difference?