Doing too many courses at the same time, leading to a situation where your days at school are long and tiresome (I don't mean boring - it's interesting really, it's just tiring) enough to make you think you have "earned" an evening of lazing around or else are just too plain tired to do anything, which leads to never doing your homework which leads to the days being more tiresome since it's harder to catch up if you haven't worked in the evening at all...
Bah.
I should have done something like a million things today but ended up doing only one.
Meaning more work tomorrow, meaning more work the day after tomorrow, meaning eventually more work for the weekend, which is in practise more work left undone, which ends up as more work for the exam week.
And no, I'm not stressed.