Exactly! 30 seconds is just a glimpse of an eye. Just a deep breath before trying to say something. You're trying to remember their name and your own name but some child swinging in a swing and that swing squeaking distracts you. And the nose hair dangling out the persons nose takes all the energy reserved for you to concentrate on their name. So unless the persons name is Squeaky Nosehair, it's impossible to remember their name afterwards. Like 30 seconds after or any time after that.

Except on some cases, about 5 years later, in the middle of the night, in bed, when you're to sleep, you suddenly get a flashback of that situation and you can stop and rewind that flashback in your brain as many times you want and also hear what that person said. Not remember the name but hear it for the first time ever. For six hours so that in the morning, having slept only two hours, the name of that person is the only thing your brain can remember.

I’ve always felt compliments should not be given easily

That depends. If I've done for example an excel form and someone says how skillful I am, I instantly think that they are just being mean or have an ulterior motive. If that person is someone who I think has normal skills like any of us and doesn't have any excuse not do the same I've done.

I remember one former acquaintance that used that to people, compliment them but right after ask that person to do that same thing for her, obviously because she was just plain lazy and wanted to take advantage of that ego boost. And the little and not so little things she asked were of course as a favor to a friend so bigger jobs did not include any money transactions or she offered something in return that the other person didn't want. "Here's a coffee package that is dated 2001 which I opened last month but it's still good. Take it!" _{Just an example, she didn't do that, but similar things.}

Thank goodness she's a former acquaintance.