Yepyepyepyep -- I struggle mightily with this phenomenon and some time ago adopted the above practice [except my variant is 'good to see you'; my farewell is 'see you later / see you around' for consistency].

Has saved me a hella ton of aggravation and worrying.

edit : if I know from context that I've met someone before but don't recognize them / remember name, I just come right out and admit it straight away : "Hi! We met before but I've forgotten your name, sorry -- what is it?"

Apparently "nice to see you" is a Hollywood thing, I remember a guest (an actor) on a talk show saying "I hate when people say that, it's so phony!"

Ha ha I thought it was a Washington DC thing, where politicians and important people are constantly meeting lots of people so it's a good weasel word.

I go with, "What's your name again?". When they tell me their first name, I say, "No sorry, I meant your last name?".

Works every time.

No it doesn’t. Everyone with a mild bit of common sense knows what you’re doing

What, they refuse to answer? How rude.

They’ll play along, but be aware that not only have you forgotten their name, you also believe you can fool them into thinking you didn’t

Yeah it's double patronizing. It's worse than just coming clean and shifting the burden to yourself by acknowledging your poor memory skills.

The goals wasn't to relearn their name, but to relearn it while not showing that you forget it. The latter part is what fails...

As rude as lying to save face?

The lie would be for the benefit of the person whose name was forgotten, not to "save face". From what, forgetting a name? Nothing is more human.

I do agree that to lie at all is a terrible idea.

Now I'm curious. If lying in general is a terrible idea, how does the person whose name was forgotten benefit, otherwise what makes the terrible lie worth it?

White lies are confusing things.

Why would you be asking what someone's last name is, especially by asking "what's your name again?"

Neat trick but it shouldn't be the only one you have. Which is to say it isn't the best way to proceed.