i had a really good day today (thursday) so will someone please tell me why i tear when im happy and cry when i laugh?

they were definitely not tears of joy.

while being thoroughly entertained by the antics of the hilarious mascots at the cheerleading competition tonight, tears suddenly sprang into my eyes and my throat tightened. i felt my grin melting away into a quivering line and my facial muscles twitching slightly. it was like i had no control over them. i have no idea why. one second im laughing at the performance, and the next, i feel like bursting into tears. reading a particularly funny paragraph in someone's blog triggers the boohoos too.

i want to know why i reacted the way i did and feel the way I do.

i seldom cry when im feeling sad anymore so it's even more puzzling that i should feel like crying when im actually happy.

is something very wrong with me?

and why the hell am i still awake at 4am...?