Seriously, if you don't know, look it up before proceeding: patella.
I attended a very informative sales meeting / product demo on Wednesday. The product will provide a lot of useful features for us, and allow us to prove it when we say busted shit ain't our fault.
But the guy doing most of the demo told a story that really destroyed his credibility.
A few months ago he hurt himself playing basketball. He was in excruciating pain, but figured that he'd finally torn his ACL, making him a "real" basketball player. So he went to a doctor who assessed the situation and said she was fairly confident he had only dislocated his knee cap, and that she could reset it for him with no real problem. He said that he'd rather get a second opinion first, and went on his painful but merry way.
The 2nd doctor told him that he'd "busted" his patella and put him on the long slow road to recovery.
Then came the curious grandstanding, meant to show that sometimes the advice you get early on can lead to greater harm down the road: "What if I'd taken that first doctor's advice? What kind of pain would I be in today? I mean, it wasn't my knee cap: it was my patella! It had nothing at all to do with my knee cap!"