> Imagine, for example, in an Optional based language, that you just map the optional to a lambda to execute on the optional, and the behaviour of the optional

> Imagine, for example, in an Optional based language, that you just map the optional to a lambda to execute on the optional, and the behaviour of the optional is to then simply silently do nothing if it's optional.none. That'd be a much harder to find bug than a nullpointer error. It's worth noting that this is only possible if the operation you're mapping over the optional can have side-effects. Without side-effects, mapping over an optional always does nothing, in a way - all the difference is in the value returned. Adding that constraint does make programming pretty painful, though.