Osmanthus Wine is, pretty self explanatorily, a type of wine made out of osmanthus, a plant that grows on the form of shrubs or small trees (mainly on Asia).
Commonly used as a joke between Genshin Impact players, as it is part of a voiceline repetitively said by the character Zhongli;
“Osmanthus wine tastes the same as I remember, but where are those who share the memory?”
Nobody knows what the memory is, now who are “those who share it”.
Person A: “I finally drank Osmanthus Wine after so long.”
Person B: “Does it taste the same as you remembered?”
Person A: “Yes, but where are those who share the memory?”
12 step recovery jargon referring to someone new who talks about how great life is, now that they're sober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.