There is also the one where you use a bent wire to score the plastic liner on the inside of the can then put the acid in the can and swirl it around and pour it out. This leaves the can looking perfectly normal but makes it so you can easily rip the can perfectly in two to the amazement of your chemistry students.

When I was still at university (20+ years ago) a girl asked my to help her figure out why her Internet in her dorm room wasn’t working. My first question was “is it plugged in?” She said it was, so that evening I went to her room to check it out. First thing I did was find the end of her network cable and plug it back into her computer. When I pointed out that she had said it was definitely plugged in she responded with “I thought you meant the power cable”. I almost pointed out that if the power cable was not plugged in then I’m pretty sure she would not have been complaining that the internet was not working but at this point it was obvious that she was just using her “computer problems” to get me to come to her room and that she was the one that unplugged the cable. The most ridiculous part is that all she had to say was “hey, you should come to my room” and I would have happily obliged.