It really depends on the context. What was the first encounter? If it was a first date, then yeah, that’s brutal and you suck. If it was a quick intro at a busy event, it’s almost expected.
There’s a bit of a difference between names and faces. Forgetting a name is like forgetting a piece of trivia, but if you meet and speak to somebody and can’t recognize them in a different context (and they look basically the same), it can send a signal that you didn’t find them memorable (and you didn’t lol).
The only time in my life when I found it irritating was my best friend’s roommate who, after hanging out with them in small groups dozens of times for hours each time, still kept introducing herself to me on subsequent visits. I could never figure out if it was drugs, a method of humour or flirting I didn’t understand, or she was really that oblivious to other people.
I was on a third date, and we met an acquaintance of mine. I went to introduce them and blanked. Worse, I went for what I thought I remembered, which ended up close enough to be culturally insensitive. His name was Franz and I said Fritz and he was pretty hurt.
That just seems petty. They both sound like generic German names to me. There even used to be a Kaiser named Fritz.
Just recently I was asking someon "was your name James?" reply: "no, Jason". It was a non-issue