How can one dose make such a difference?

i wanted to stay up and watch the leonid shower last night so i didn't take my evening dose of lamictal; i didn't want to be too sleepy to go skywatching, a wasted effort since i fell asleep anyway. the last couple of days have been okay and i've been very good about being med compliant (especially with my morning meds). so i reckoned one dose wouldn't make all that much of a difference, right? wrong. i woke up crying and out of sorts. i feel really off-keel and depressed and it's like the okay days never happened at all. i feel just awful about everything. it's just...one of those dark blue days and maybe if i had taken my meds it wouldn't be.  i don't like that i'm so dependent on medication, but it is what it is. not taking meds isn't really an option. days like today are a good reminder of why that is.  days like today make me want to curl up and wait for the world to pass me by. it's such a blue blue day.