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1.
The adverse effects one endures mentally from over-thinking things; usually secrets, inside information, or just the side effects of an over-active imagination.
You wanna know what Thought Cancer™ is?

You're cool with a guy. He settles down with a 'used-to-be' 'round-the-way' girl. They're all lovey dovey and stuff... You have a porno or two of her. You and him are supposed to be good, you and her talk. You start wondering:

Do I tell him?
But suppose he already knows?
But suppose he doesn't know?
Then she's gonna get upset with ME?
But I never told her to film her sexual exploits?
But it's none of my business anyways?
But they look so happy and I'm not the only one with the tape?
He might be upset that I know about it and didn't tell him?
Why did I have to see the damn tape?
Why do they have to be all over the place all lovey dovey?

Before you know it, you're failing exams, losing weight, can't fuck properly, drinking, chain-smoking... all the while the thought cancer is eating away at your psyche.
by WeASeL_Antigua June 29, 2011