Agriculture and advanced culture may have existed prior to the event, but it looks like the source for flood myths. Aside from Gobekli Tepe and a handful of other sites, it appears most knowledge and culture was lost. People had to start from scratch, so agriculture begins at most 12,000 years ago, comprising almost every plant we eat today. There's no way to know what might have been utterly lost.
There's evidence of modern humans going back almost 300,000 years. (Crazy to think we were without dogs for ~260k years. Humans are better with dogs around. )
Humans probably invented language and writing and all sorts of proto-sciences many times over those hundreds of millenia, but everything before 12,000 years back is gone. There's virtually no evidence of the vast majority of human culture before then. Entropy sucks.