Absolutely! I have similar stories with other abstractions too (virtual methods, protocols, exceptions etc) I just never quite understood where this "don't wor

Absolutely! I have similar stories with other abstractions too (virtual methods, protocols, exceptions etc) I just never quite understood where this "don't worry about the implementation" is coming from, as well as the tendency to explain abstractions in general terms, with analogies that make little sense, etc. The "don't worry about the implementation" did so much harm to humanity by producing bloated, wasteful software. In fact I think a good abstraction is the one (1) whose implementation can be explained in clear terms, and (2) whose benefits are as clear once you know how it's implemented.