If we assume the pre-Flood world had ideal living conditions, their memory, wisdom, and accumulated knowledge would have been incredible! How much could you learn in 900 years?! Add to that the fact that you can go talk with your great-great-great-great-great-great-grandfather, who is still living. You can learn from them and build on that knowledge. Plus, don't forget that Methuselah could have known Adam for 243 years and learned from him; and Adam walked and talked with God Himself for maybe 100 years! I suspect the pre-Flood knowledge and maybe even technology and inventions would blow our minds today!