My mom used the top oven to store our bread. After a few times of smelling the burnt bread and plastic, we took the knob off.
Never, ever stick your finger near the blade of a drink blender (similar to this one. I ended up with the blade lodged through my thumbnail. My dad had to cut the plastic surrounding to dislodge my finger. He was more freaked out than I was. I just stood there and said “Um… I need help.” with the blender hanging off of my thumb.
When a tornado blows through your workplace’s parking lot in the dead of night, it’s a good idea not to go walking through the parking lot to survey the damage.
This actually happened to me. I was walking around “oohing” and “aahing” at the destructive power of an F2, and decided to walk down to the sidewalk and take a look at the damage on the street. After getting my fill, I looked down at my feet and saw that my knees were about an inch in front of a downed power line. :smack:
I was trying to clean the hair out of my razor once. I was smart enough not to do it with my bare hand. So I used a piece of toilet paper, instead. Surprisingly enough, not even two-ply toilet paper is sufficient to protect your fingers from razor sharp steel.
One I learned - again - just now. Don’t blow out a lit match while holding it above a full ashtray. 'Scuse me whilst I fetch a paper towel…
One I learned as a young lad: Do not, when pretending to be a ninja turtle, stand on the glass-topped patio table while demonstrating your bo staff skills.
One my dad learned when I was a young lad: yes, the glue that comes out of the glue gun really is that hot, and your son is not just being a crybaby. Seriously: what kind of moron lets their eight year old son play with an industrial glue gun? Apparently, the same kind of moron who, after their son has been whisked away to the emergency room to be treated for his burn, thinks to himself, “It can’t be that hot,” and squirts a dollop of hot glue into the palm of his own hand?
Seriously, I love my dad, and he’s easily the smartest person I know, but he simply should never have been placed in charge of a young child. I broke my arm in the third grade. Turns out the cast hadn’t been wrapped tightly enough, and the bones shifted before they started mending, meaning my arm had to be re-broken. The doctor asked my dad if I should be given a shot for the pain, and my dad let me decide. I’m in the third fucking grade! I don’t even know what they’re talking about, I just know I don’t like needles! Of course I said no! I learned, that day, to never, ever, ever say no to a painkiller.
Sip soda pop while sucling on a Mentos.
Do not attempt to take an air conditioner out of a window by myself. I’m glad I wasn’t alone in the house - I would have bled to death because I passed out when I saw the tendons in my left arm. 69 stitches later I have lovely scars on both arms.
I also learned if you break the fifth metatarsal away from the ankle and walk before it swells, you might re-set it and save yourself surgery. The doctor said that is what I did - I saw the bone pressed up against the skin of my foot, but walked a block and a half to get to my Jeep. Thank goodness it was my accelerator foot instead of the clutch foot or I would have never made it home. My foot was purple from my toes to halfway up my shin.
Do not, under any circumstances set a hot, glass loaf pan straight out of the oven onto a cool, wet counter top. It will explode, scare the bejeebus out of you, your husband and the cat.
Oddly enough, I was standing inches from it and got no glass on me at all, not a scratch, even though the pan was in a zillion pieces. Yep, that just confirmed what I already suspected, I am a superhero. 
Oh gawd, that reminds me of something else.
There is a very good reason why one should never put a dead match back into the matchbox. Sometimes they’re not quite dead. :eek:
Something my dad learned as a child: Yes, a bullet will explode if you hit it with a hammer, but it’s not a good idea.
On a related note, I learned not to mention “that time you [Dad] hit a bullet with a hammer” in front of my grandparents, because it’s possible that Dad never actually told his parents the truth about where that cut on his arm came from.
Speaking of bullets: You do not have to try this to see if it will work. Trust me. We figured it out experimentally when we were kids:
Yes, if you set a shotgun shell on a fencepost, stand back 30 feet, and shoot the primer with a BB gun, the shell will explode.
From a news article - Do not attempt to have sex with a hedgehog in order to cure premature ejaculation! link
Yes, you can impress kids by setting your hand on fire using 50% alcohol and put it out with just a big wave of the hand, but don’t try it with pure alcohol.
Owie.
Things are different in other countries… box wine doesn’t necessarily have the “Good Trailer-Houskeeping” seal of approval elsewhere.
As for the danger pudding… it’s a lot safer if you open the can of sweetened condensed milk and put it in a water bath inside a pressure cooker.
OB Thing not to do:
After soldering various things, don’t assume that the soldering iron has already cooled off when you go to pick it up. Definitely don’t pick up the soldering iron by the assumed-to-be cool tip. I had two really nice blisters across my index finger and thumb of my right hand for a while after that.
Another molten wax Don’t is this: Do not extinguish a tealight candle in a glass holder by blowing directly down on it from above, unless you want to be peeling solidified wax off your eyeballs.