A/N #1: Yay! I thought of some more things! :)
I realize that half of the things here could be classified as "you know you're obsessed with Colin Morgan / Bradley James" rather than just Merlin. But hey, it's all in the same category. ;)
PART 2:
You know you're obsessed with Merlin when...
One of your friends says something stupid to which you stare at them utterly bewildered and reply, "Have you some sort of mental affliction?"
You reconsider the idea of dyeing your hair red because you know Colin's feelings towards gingers.
You wish one of your professors would become possessed by a goblin for a day.
You suddenly want to make and wear a blue or red neckerchief (because apparently that's the best way to show your Merlin support!)
You wish your name was Zoe.
Any conversations about spiders come up and you exclaim, "How big was that spider?" in an Irish accent.
You're given a difficult project or assignment and cheerily chant, "We're gonna die! We're gonna die!"
You feel extremely sad every time you see a beautiful lake because you think of Freya and Merlin's all-too-short relationship.
You find yourself mimicking Gwaine's drunken movements.
Your parents have walked in on your when you were pretending to have a sword fight in your room.
You see an orangish-gold stone on a piece of jewelry and you immediately gasp because you think it's the eye of a phoenix.
You use the phrase, "I'm begging you", and it is immediately followed by, "We will leave Camelot, and never return!"
You find yourself muttering some of the spells.
You watch episodes you've already seen whenever they come on tv, even though you can watch them online anytime.
You're taking an exam in a foreign language class, and the only thing that comes to mind for campfire is "forbearnan".
A/N #2: Hope this brought a smile to your face! Again, if I accumulate any more interesting ones that I'm guilty of, I'll post another chapter. ;)