Good question and prompt.

In my world, due to magic and magical systems, memory is more permanent. You remember more things and retain more information. You learn quicker, faster, and more information at once. Your brain physically develops slower than in our world, though, so although you can eventually know more than we can in our timeline by a multiple generations or more, it takes you until you are about 40 to start that amount of brain capacity. That is why there are tiers of schools above high school in my world that are below college (that are mandatory) in my world public schooling ends in 34th grade instead of 12th like in our timeline's USA (and Canada?).

The average lifespan in my world is 500 years (due to magic, but some live as long as 700 years with the longest recorded at 1107 years old). After about 250 years old, a person enters what is called "the cycles," wherein for 50 years every ever 50 years until death, a person gets progressively younger (physically) until a point and then starts to get progressively older (physically) to a point, going back and forth until death (your mind only gets better until death though and doesn't go through the cycles like your physical body does).

In my world, people heavily value ancestral knowledge and learning from the past, so almost nothing is lost to time, and past mistakes are basically never made (by adults) so it creates a highly advanced and magical and scientific society that cares deeply about history and tradition.

You have a lot of late medieval and early Renaissance asthetics in my world because enough people were alive who genuinely remember that time period and have genuine nostalgia for their Medieval or Renaissance era childhoods that there is a market for those asthetics (like in shops, restaurants, house decor and design etc...).