My friend Jonathan Baker handed a banana and a knife to every student in his Bible classes at Puebla Christian School in Puebla, Mexico. He told them to cut up their bananas any way they wanted. Junior high boys pretty much decimated theirs while other students cut their bananas into large pieces.
Then Jonathan passed out cellophane tape and told them to put the bananas back together again. It was, of course, a mess. The students who had made neat cuts with their knives were able to reassemble their bananas, but even with tape it was clear they were in parts. The mashed bananas, needless to say, were hopeless. Even with tape.