Have you ever been stuck trying to understand your code and logged the contents of a variable? NSLog(@"%@", whatIsInsideThisThing); Or skipped a function call to simplify the behavior of the program? NSNumber *n = @7; // theFunctionThatShouldReallyBeCalled(); Or short-circuited a logical check? if (1 || theBooleanAtStake) { ... } Or faked the implementation of a function? int calculateTheTrickyVal