I remember being about 13 and learning about OO code and reading Apple's (then excellent) developer documentation. It had an example of a class called "faucet" and lots of text related to American plumbing. At the time I had literally no idea what faucet meant (en_gb: tap) and spent about five times longer trying to understand the metaphor than the actual code. It really left a bitter taste in my mouth: I didn't have a clue what was going on, not because of inheritance or Obj-C, but entirely because I didn't understand what the author probably didn't realise was a culturally sorry metaphor.