Pro Tip #1: These are things you shouldn't attempt to ingest.

I DO THIS SO THE WORLD MAY BENEFIT FROM ALL THE WAYS IN WHICH I FAIL.

Candle wax.
It was a particularly large uni night - it reached McConaughey status, for those of you playing at home - when it happened. We were sitting at a table at the Toff, next to the D-Floor. My drink was sitting next to a candle on said table. Probably amidst my making some sort of grand statement backed up with nothing more than alcohol-fuelled "smarts", I raised the wrong glass to my lips and drank the wax from the candle. Okay. So. Even if much of the night is a laughter-filled blur, this memory is crystal-clear in my memory. I could feel the wax my mouth, burning then setting. It started to go down my throat. I screeched in horror, and jumped up with my hands clawing at the inside of my mouth. I must have looked like I was possessed. I sprinted away towards the bathroom, gagging and choking and wretching. I pushed past the line for the loos, spitting out wax. It was one of the most unpleasant things I have ever done. I was coughing and my hands were digging at the sides of my mouth, wax was on the floor. Look, it probably wasn't that bad/terrifying, but in my memory it was pretty much the most traumatic thing you can imagine. At one point I remember thinking to myself, "IS THIS HOW IT ENDS? CHOKING TO DEATH ON CANDLE WAX?"

"She died as she lived, constantly failing at things"

When I returned to my pals, I learned that almost as soon as I'd abruptly left in a swirl of red dress and red face and gag reflex, Immy had almost been involved in a dance-floor brawl. This potential brawl was then averted by our male uni compadres, who suddenly as one became some sort of Power Rangers-esque squad of badassery. Me? I was nowhere to be seen. I was busy trying to extricate bits of candle from my esophagus.
NEVER AGAIN.

A spoonful of cinnamon.
The cinnamon challenge never, ever ends well.

Your body weight in banana lollies.

I did this when I was a kid and now can't even look at the little pale yellow fuckers without wanting to chum. While eating, OCCASIONALLY CONSIDER PAUSING.

What you think is chocolate on your floor but is really just a clump of dirt.
I think this one's self-explanatory.

Not awesome. A clump of dirt.

Salpicon de pollo. 
When travelling, one is constantly reminded to "Steer clear of mayonnaise! And chicken!". One is also urged to always gravely consider the cleanliness of any street-side food vendor one may be thinking of hitting up for a snack. Salpicon de pollo is can best be described as a kind of salad-y type deal with a whole lot of chicken, lathered in mayonnaise. Obviously that's what I chose to eat on my second day in Cusco. And obviously I was too excited about food or too excited about my lunch companion's Top Five Films to notice I was dancing with salmonella risk. The result?
I GOT SALMONELLA. 
Seriously, I was asking for it. I was pretty much waving my arms around yelling, "PICK ME! PICK ME!".
Needless to say, the results were far from pretty. You haven't seen shame and agony until you've seen me sitting on the toilet while throwing up into the shower. I threw up everything I ate for a week before dragging myself to a hospital. I threw up everything, all the time for a week. Keep in mind this happened on my second day in Cusco, my first day of Spanish classes. I barely got to know my host family because I was too busy trying to sleep away the nausea, in between sporadic sprints to the bathroom. Also, please keep in mind the fact that you can't flush toilet paper down the toilet in South America. It was truly a comedy of errors. At one point I decided I was getting better, and so went out for a drink with Colin (he who was there at the Great Poison Salpicon de Pollo) and Remi. Half a beer and a excruciating walk home later, I was in the throes of a battle in chunderland.
The next day I almost passed out walking up the hill to school, fell into the classroom and managed to get out (in Spanish),
"I HAD BEER. I NEED A DOCTOR"
Halfway to the hospital, I lost my directions to the hospital. When I finally got there, I declared my food-poisoning to be "muy horrible". They countered with, "Yes, because you have salmonella". They wanted me to stay overnight, but refused because I didn't want to be away from my friends (read: I'm a big ol' chicken). So they gave me about a thousand different types of medication and sent me on my nauseous, slightly delirious way. I was alcohol-free, delicious food-free, and dosed up for another week and a half.
Steer clear of mayonnaise and chicken.

Rookie mistake.