mondays

so, what is the big difference between mondays and sundays? i get up the same time on each day (not because I like it because my body does it to me) I work all the time, but for some reason it is so much harder getting up and out of bed on monday than it is on sunday. I know I am not alone on this, but I don't know how to make it any easier. I don't have to get up early (got up at 8am this morning) which is enough sleep for me, but still, maybe its because i have to go to work or be away from the house. not sure but it is really hard to get up on mondays!