"Oh, God, the aftertaste!"

you probably think you're pretty cool

you probably know i am

This one counts as nasty...and my all time dumbest moment ever.
I work at a hotel, 3rd shift. I had just set breakfast, and a woman came out and told me the milk had gone sour. I replaced the half gallon, and brought the old one in back.
I smelled it...it smelled fine.
I looked at the date. Still fine.
"She's gotta be wrong", I thought to myself, "I just opened this a few hours ago."

So I took a sip.

Yup...she was right. It was sour.

As for things that would gross people out...that I LIKED...
I once ate raw venison.
It was delicious.

I once poured myself a bowl of Bart Simpson cereal and after a few bites, realized it was infested with a bunch of little black bugs. That was gross.