If a fae lord appears and is like "And can I have your name?" and I say "Yeah it's Eric"

That's not my name anymore

This is a given

But just like

"Hey what's your name"
"Eric"

That should be fine

Right?

Like the implication is not "If fairies know your name they can steal it"

It's "If they use tricky wording to make you agree to give up your name without realizing it, then they can steal it"

The implied agreement

There's also often lore about how knowing someone's true name gives you power (or an unspecified sort?) over them.

Which then can lead into the debate of what exactly counts as a "true" name.

Is my True Name just Eric?

would it be my full legal name?

I need to be prepared if I meet a mysterious stranger in the woods with moonlight in their eyes

There's some slight variation, but the general idea is that if you tell them what your name is, that's dangerous. If they just overhear it from someone else, then I don't think they can use it the same way, but I would not exactly want to gamble on that.

Treat fae like you're supposed to treat the internet and assume anyone who has knowledge of your identity can use it for ill purposes.

Internet safety is just rediscovering true name magic

If I know your login information True Name, I can take on your identity and steal your power

So what I'm hearing is, we need to use tales of the Fae to teach the young ones internet security?

Also the old ones

Yeah it varies but commonly "giving" then your name allows them to assume your identity and "telling" them your name allows them to assert control of some kind over you

Safest option is to tell them a name that not only is not yours but will cause some kind of semantic confusion if they try to invoke it.

The Odysseus defense

Yep.

sometimes there is also a defense in being more sure of your identity and selfhood than the faeries can deal with
but that's generally more modern stuff

the granny weatherwax defense

There's a running gag in the trans community that most of us would love to meet a fae and then sell them our deadname. Go ahead, be the person I no longer want to be, I'll be myself whole and entire.