every sunday night i have an incredibly hard time falling asleep.

i should start by saying that normally i have zero difficulty falling asleep.  i get in bed, i read my book for 10 minutes, i turn off the light, and that's all she wrote.  often i wake up and it's clear i didn't move at all during the night - the covers are all in the same place as when i went to sleep.

perhaps it's just in comparison to this glory that sunday nights seem so bad.  on sunday nights i toss and turn - left side to back to right side to back to left side to back to right side.  i look at the clock every 10 minutes or so as i make my turn.  it's common for me to watch a whole hour go by while i try to fall asleep.

i am well-rested most sundays, so perhaps that is the issue, but i usually have a 90 minute yoga class during the day, so it's not the lack of exercise that's keeping me awake.  yes, i'm thinking about the week ahead, but i'm not worrying about anything in particular.  i try to stay up a little later on sundays so i'll be a little more tired and thus kick this cycle, but that doesn't work.  it's not caffeine, since i don't drink much diet coke at all any more.

ugh.

does anyone else share this problem?  any good suggestions for how to fix it?